diff --git a/doc/release-notes.md b/doc/release-notes.md
index 3aa6cbc94..20b97afd0 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -1,12 +1,18 @@
 Bitcoin ABC version 0.20.5 is now available from:
 
   <https://download.bitcoinabc.org/0.20.5/>
 
 This release includes the following features and fixes:
+ - It is now possible to unload wallets dynamically at runtime. This feature is
+   currently only available through the RPC interface.
+
+GUI changes
+-----------
  - Wallets loaded dynamically through the RPC interface may now be displayed in
    the bitcoin-qt GUI.
  - The default wallet will now be labeled `[default wallet]` in the bitcoin-qt
    GUI if no name is provided by the `-wallet` option on start up.
- - It is now possible to unload wallets dynamically at runtime. This feature is
-   currently only available through the RPC interface.
  - Wallets dynamically unloaded will now be reflected in the gui.
+ - Block storage can be limited under Preferences, in the Main tab. Undoing
+   this setting requires downloading the full blockchain again. This mode is
+   incompatible with -txindex and -rescan.
diff --git a/src/qt/forms/optionsdialog.ui b/src/qt/forms/optionsdialog.ui
index a3721991e..8f34e6bc8 100644
--- a/src/qt/forms/optionsdialog.ui
+++ b/src/qt/forms/optionsdialog.ui
@@ -1,837 +1,900 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
  <class>OptionsDialog</class>
  <widget class="QDialog" name="OptionsDialog">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>560</width>
     <height>440</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>Options</string>
   </property>
   <property name="modal">
    <bool>true</bool>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
       <number>0</number>
      </property>
      <widget class="QWidget" name="tabMain">
       <attribute name="title">
        <string>&amp;Main</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_Main">
        <item>
         <widget class="QCheckBox" name="bitcoinAtStartup">
          <property name="toolTip">
           <string>Automatically start %1 after logging in to the system.</string>
          </property>
          <property name="text">
           <string>&amp;Start %1 on system login</string>
          </property>
         </widget>
        </item>
+       <item>
+        <spacer name="horizontalSpacer_0_Main">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>5</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_Main_Prune">
+        <item>
+         <widget class="QCheckBox" name="prune">
+          <property name="toolTip">
+           <string>Disables some advanced features but all blocks will still be fully validated. Reverting this setting requires re-downloading the entire blockchain. Actual disk usage may be somewhat higher.</string>
+          </property>
+          <property name="text">
+           <string>Prune &amp;block storage to</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="pruneSize"/>
+        </item>
+         <item>
+          <widget class="QLabel" name="pruneSizeUnitLabel">
+           <property name="text">
+            <string>GB</string>
+           </property>
+           <property name="textFormat">
+            <enum>Qt::PlainText</enum>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <spacer name="horizontalSpacer_Main_Prune">
+           <property name="orientation">
+            <enum>Qt::Horizontal</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>40</width>
+             <height>20</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <widget class="QLabel" name="pruneWarning">
+         <property name="text">
+          <string>Reverting this setting requires re-downloading the entire blockchain.</string>
+         </property>
+         <property name="textFormat">
+          <enum>Qt::PlainText</enum>
+         </property>
+        </widget>
+       </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_2_Main">
          <item>
           <widget class="QLabel" name="databaseCacheLabel">
            <property name="text">
             <string>Size of &amp;database cache</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>databaseCache</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QSpinBox" name="databaseCache"/>
          </item>
          <item>
           <widget class="QLabel" name="databaseCacheUnitLabel">
            <property name="text">
             <string>MB</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
           </widget>
          </item>
          <item>
           <spacer name="horizontalSpacer_2_Main">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>
            <property name="sizeHint" stdset="0">
             <size>
              <width>40</width>
              <height>20</height>
             </size>
            </property>
           </spacer>
          </item>
         </layout>
        </item>
        <item>
-        <layout class="QHBoxLayout" name="horizontalLayout_3_Main">
+        <layout class="QHBoxLayout" name="horizontalLayout_Main_VerifyLabel">
          <item>
           <widget class="QLabel" name="threadsScriptVerifLabel">
            <property name="text">
             <string>Number of script &amp;verification threads</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>threadsScriptVerif</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QSpinBox" name="threadsScriptVerif">
            <property name="toolTip">
             <string>(0 = auto, &lt;0 = leave that many cores free)</string>
            </property>
           </widget>
          </item>
          <item>
-          <spacer name="horizontalSpacer_3_Main">
+          <spacer name="horizontalSpacer_Main_Threads">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>
            <property name="sizeHint" stdset="0">
             <size>
              <width>40</width>
              <height>20</height>
             </size>
            </property>
           </spacer>
          </item>
         </layout>
        </item>
        <item>
         <spacer name="verticalSpacer_Main">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tabWallet">
       <attribute name="title">
        <string>W&amp;allet</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_Wallet">
        <item>
         <widget class="QGroupBox" name="groupBox">
          <property name="title">
           <string>Expert</string>
          </property>
          <layout class="QVBoxLayout" name="verticalLayout_2">
           <item>
            <widget class="QCheckBox" name="coinControlFeatures">
             <property name="toolTip">
              <string>Whether to show coin control features or not.</string>
             </property>
             <property name="text">
              <string>Enable coin &amp;control features</string>
             </property>
            </widget>
           </item>
           <item>
            <widget class="QCheckBox" name="spendZeroConfChange">
             <property name="toolTip">
              <string>If you disable the spending of unconfirmed change, the change from a transaction cannot be used until that transaction has at least one confirmation. This also affects how your balance is computed.</string>
             </property>
             <property name="text">
              <string>&amp;Spend unconfirmed change</string>
             </property>
            </widget>
           </item>
          </layout>
         </widget>
        </item>
        <item>
         <spacer name="verticalSpacer_Wallet">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tabNetwork">
       <attribute name="title">
        <string>&amp;Network</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_Network">
        <item>
         <widget class="QCheckBox" name="mapPortUpnp">
          <property name="toolTip">
           <string>Automatically open the Bitcoin client port on the router. This only works when your router supports UPnP and it is enabled.</string>
          </property>
          <property name="text">
           <string>Map port using &amp;UPnP</string>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QCheckBox" name="allowIncoming">
          <property name="toolTip">
           <string>Accept connections from outside.</string>
          </property>
          <property name="text">
           <string>Allow incomin&amp;g connections</string>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QCheckBox" name="connectSocks">
          <property name="toolTip">
           <string>Connect to the Bitcoin network through a SOCKS5 proxy.</string>
          </property>
          <property name="text">
           <string>&amp;Connect through SOCKS5 proxy (default proxy):</string>
          </property>
         </widget>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_1_Network">
          <item>
           <widget class="QLabel" name="proxyIpLabel">
            <property name="text">
             <string>Proxy &amp;IP:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>proxyIp</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QValidatedLineEdit" name="proxyIp">
            <property name="minimumSize">
             <size>
              <width>140</width>
              <height>0</height>
             </size>
            </property>
            <property name="maximumSize">
             <size>
              <width>140</width>
              <height>16777215</height>
             </size>
            </property>
            <property name="toolTip">
             <string>IP address of the proxy (e.g. IPv4: 127.0.0.1 / IPv6: ::1)</string>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLabel" name="proxyPortLabel">
            <property name="text">
             <string>&amp;Port:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>proxyPort</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLineEdit" name="proxyPort">
            <property name="minimumSize">
             <size>
              <width>55</width>
              <height>0</height>
             </size>
            </property>
            <property name="maximumSize">
             <size>
              <width>55</width>
              <height>16777215</height>
             </size>
            </property>
            <property name="toolTip">
             <string>Port of the proxy (e.g. 9050)</string>
            </property>
           </widget>
          </item>
          <item>
           <spacer name="horizontalSpacer_1_Network">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>
            <property name="sizeHint" stdset="0">
             <size>
              <width>40</width>
              <height>20</height>
             </size>
            </property>
           </spacer>
          </item>
         </layout>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_2_Network">
          <item>
           <widget class="QLabel" name="proxyActiveNets">
            <property name="text">
             <string>Used for reaching peers via:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QCheckBox" name="proxyReachIPv4">
            <property name="enabled">
             <bool>false</bool>
            </property>
            <property name="toolTip">
             <string>Shows if the supplied default SOCKS5 proxy is used to reach peers via this network type.</string>
            </property>
            <property name="text">
             <string/>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLabel" name="proxyReachIPv4Label">
            <property name="text">
             <string>IPv4</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QCheckBox" name="proxyReachIPv6">
            <property name="enabled">
             <bool>false</bool>
            </property>
            <property name="toolTip">
             <string>Shows if the supplied default SOCKS5 proxy is used to reach peers via this network type.</string>
            </property>
            <property name="text">
             <string/>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLabel" name="proxyReachIPv6Label">
            <property name="text">
             <string>IPv6</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QCheckBox" name="proxyReachTor">
            <property name="enabled">
             <bool>false</bool>
            </property>
            <property name="toolTip">
             <string>Shows if the supplied default SOCKS5 proxy is used to reach peers via this network type.</string>
            </property>
            <property name="text">
             <string/>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLabel" name="proxyReachTorLabel">
            <property name="text">
             <string>Tor</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
           </widget>
          </item>
          <item>
           <spacer name="horizontalSpacer_2_Network">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>
            <property name="sizeHint" stdset="0">
             <size>
              <width>40</width>
              <height>20</height>
             </size>
            </property>
           </spacer>
          </item>
         </layout>
        </item>
        <item>
         <widget class="QCheckBox" name="connectSocksTor">
          <property name="toolTip">
           <string>Connect to the Bitcoin network through a separate SOCKS5 proxy for Tor hidden services.</string>
          </property>
          <property name="text">
           <string>Use separate SOCKS&amp;5 proxy to reach peers via Tor hidden services:</string>
          </property>
         </widget>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_3_Network">
          <item>
           <widget class="QLabel" name="proxyIpTorLabel">
            <property name="text">
             <string>Proxy &amp;IP:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>proxyIpTor</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QValidatedLineEdit" name="proxyIpTor">
            <property name="minimumSize">
             <size>
              <width>140</width>
              <height>0</height>
             </size>
            </property>
            <property name="maximumSize">
             <size>
              <width>140</width>
              <height>16777215</height>
             </size>
            </property>
            <property name="toolTip">
             <string>IP address of the proxy (e.g. IPv4: 127.0.0.1 / IPv6: ::1)</string>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLabel" name="proxyPortTorLabel">
            <property name="text">
             <string>&amp;Port:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>proxyPortTor</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLineEdit" name="proxyPortTor">
            <property name="minimumSize">
             <size>
              <width>55</width>
              <height>0</height>
             </size>
            </property>
            <property name="maximumSize">
             <size>
              <width>55</width>
              <height>16777215</height>
             </size>
            </property>
            <property name="toolTip">
             <string>Port of the proxy (e.g. 9050)</string>
            </property>
           </widget>
          </item>
          <item>
           <spacer name="horizontalSpacer_4_Network">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>
            <property name="sizeHint" stdset="0">
             <size>
              <width>40</width>
              <height>20</height>
             </size>
            </property>
           </spacer>
          </item>
         </layout>
        </item>
        <item>
         <spacer name="verticalSpacer_Network">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tabWindow">
       <attribute name="title">
        <string>&amp;Window</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_Window">
        <item>
         <widget class="QCheckBox" name="hideTrayIcon">
          <property name="toolTip">
           <string>Hide the icon from the system tray.</string>
          </property>
          <property name="text">
           <string>&amp;Hide tray icon</string>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QCheckBox" name="minimizeToTray">
          <property name="toolTip">
           <string>Show only a tray icon after minimizing the window.</string>
          </property>
          <property name="text">
           <string>&amp;Minimize to the tray instead of the taskbar</string>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QCheckBox" name="minimizeOnClose">
          <property name="toolTip">
           <string>Minimize instead of exit the application when the window is closed. When this option is enabled, the application will be closed only after selecting Exit in the menu.</string>
          </property>
          <property name="text">
           <string>M&amp;inimize on close</string>
          </property>
         </widget>
        </item>
        <item>
         <spacer name="verticalSpacer_Window">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tabDisplay">
       <attribute name="title">
        <string>&amp;Display</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_Display">
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_1_Display">
          <item>
           <widget class="QLabel" name="langLabel">
            <property name="text">
             <string>User Interface &amp;language:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>lang</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QValueComboBox" name="lang">
            <property name="toolTip">
             <string>The user interface language can be set here. This setting will take effect after restarting %1.</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_2_Display">
          <item>
           <widget class="QLabel" name="unitLabel">
            <property name="text">
             <string>&amp;Unit to show amounts in:</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>
            </property>
            <property name="buddy">
             <cstring>unit</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QValueComboBox" name="unit">
            <property name="toolTip">
             <string>Choose the default subdivision unit to show in the interface and when sending coins.</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_3_Display">
          <item>
           <widget class="QLabel" name="thirdPartyTxUrlsLabel">
            <property name="toolTip">
             <string>Third party URLs (e.g. a block explorer) that appear in the transactions tab as context menu items. %s in the URL is replaced by transaction hash. Multiple URLs are separated by vertical bar |.</string>
            </property>
            <property name="text">
             <string>&amp;Third party transaction URLs</string>
            </property>
            <property name="buddy">
             <cstring>thirdPartyTxUrls</cstring>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QLineEdit" name="thirdPartyTxUrls">
            <property name="toolTip">
             <string>Third party URLs (e.g. a block explorer) that appear in the transactions tab as context menu items. %s in the URL is replaced by transaction hash. Multiple URLs are separated by vertical bar |.</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
        <item>
         <spacer name="verticalSpacer_Display">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </widget>
     </widget>
    </item>
    <item>
     <widget class="QFrame" name="frame">
      <layout class="QVBoxLayout" name="verticalLayout_Bottom">
       <item>
        <layout class="QHBoxLayout" name="horizontalLayout_Bottom">
         <item>
          <widget class="QLabel" name="overriddenByCommandLineInfoLabel">
           <property name="text">
            <string>Active command-line options that override above options:</string>
           </property>
           <property name="textFormat">
            <enum>Qt::PlainText</enum>
           </property>
          </widget>
         </item>
         <item>
          <spacer name="horizontalSpacer_Bottom">
           <property name="orientation">
            <enum>Qt::Horizontal</enum>
           </property>
           <property name="sizeHint" stdset="0">
            <size>
             <width>40</width>
             <height>20</height>
            </size>
           </property>
          </spacer>
         </item>
        </layout>
       </item>
       <item>
        <widget class="QLabel" name="overriddenByCommandLineLabel">
         <property name="text">
          <string/>
         </property>
         <property name="textFormat">
          <enum>Qt::PlainText</enum>
         </property>
         <property name="wordWrap">
          <bool>true</bool>
         </property>
        </widget>
       </item>
      </layout>
     </widget>
    </item>
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout_Buttons">
      <item>
       <layout class="QVBoxLayout" name="verticalLayout_Buttons">
        <item>
         <widget class="QPushButton" name="openBitcoinConfButton">
          <property name="toolTip">
           <string>Open the %1 configuration file from the working directory.</string>
          </property>
          <property name="text">
           <string>Open Configuration File</string>
          </property>
          <property name="autoDefault">
           <bool>false</bool>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QPushButton" name="resetButton">
          <property name="toolTip">
           <string>Reset all client options to default.</string>
          </property>
          <property name="text">
           <string>&amp;Reset Options</string>
          </property>
          <property name="autoDefault">
           <bool>false</bool>
          </property>
         </widget>
        </item>
       </layout>
      </item>
      <item>
       <spacer name="horizontalSpacer_1">
        <property name="orientation">
         <enum>Qt::Horizontal</enum>
        </property>
        <property name="sizeHint" stdset="0">
         <size>
          <width>40</width>
          <height>48</height>
         </size>
        </property>
       </spacer>
      </item>
      <item>
       <widget class="QLabel" name="statusLabel">
        <property name="minimumSize">
         <size>
          <width>200</width>
          <height>0</height>
         </size>
        </property>
        <property name="font">
         <font>
          <weight>75</weight>
          <bold>true</bold>
         </font>
        </property>
        <property name="text">
         <string/>
        </property>
        <property name="textFormat">
         <enum>Qt::PlainText</enum>
        </property>
        <property name="wordWrap">
         <bool>true</bool>
        </property>
       </widget>
      </item>
      <item>
       <spacer name="horizontalSpacer_2">
        <property name="orientation">
         <enum>Qt::Horizontal</enum>
        </property>
        <property name="sizeHint" stdset="0">
         <size>
          <width>40</width>
          <height>48</height>
         </size>
        </property>
       </spacer>
      </item>
      <item>
       <layout class="QVBoxLayout" name="verticalLayout_4">
        <item>
         <spacer name="verticalSpacer">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>20</width>
            <height>40</height>
           </size>
          </property>
         </spacer>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout">
          <item>
           <widget class="QPushButton" name="okButton">
            <property name="text">
             <string>&amp;OK</string>
            </property>
            <property name="autoDefault">
             <bool>false</bool>
            </property>
            <property name="default">
             <bool>true</bool>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QPushButton" name="cancelButton">
            <property name="text">
             <string>&amp;Cancel</string>
            </property>
            <property name="autoDefault">
             <bool>false</bool>
            </property>
           </widget>
          </item>
         </layout>
        </item>
       </layout>
      </item>
     </layout>
    </item>
   </layout>
  </widget>
  <customwidgets>
   <customwidget>
    <class>QValidatedLineEdit</class>
    <extends>QLineEdit</extends>
    <header>qt/qvalidatedlineedit.h</header>
   </customwidget>
   <customwidget>
    <class>QValueComboBox</class>
    <extends>QComboBox</extends>
    <header>qt/qvaluecombobox.h</header>
   </customwidget>
  </customwidgets>
  <resources/>
  <connections/>
 </ui>
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
index 86d310233..879684f25 100644
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -1,351 +1,375 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #if defined(HAVE_CONFIG_H)
 #include <config/bitcoin-config.h>
 #endif
 
 #include <qt/forms/ui_optionsdialog.h>
 #include <qt/optionsdialog.h>
 
 #include <interfaces/node.h>
 #include <netbase.h>
 #include <qt/bitcoinunits.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
 #include <txdb.h>       // for -dbcache defaults
 #include <validation.h> // for DEFAULT_SCRIPTCHECK_THREADS and MAX_SCRIPTCHECK_THREADS
 
 #include <QDataWidgetMapper>
 #include <QDir>
 #include <QIntValidator>
 #include <QLocale>
 #include <QMessageBox>
 #include <QTimer>
 
 OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet)
     : QDialog(parent), ui(new Ui::OptionsDialog), model(0), mapper(0) {
     ui->setupUi(this);
 
     /* Main elements init */
     ui->databaseCache->setMinimum(nMinDbCache);
     ui->databaseCache->setMaximum(nMaxDbCache);
+    static const uint64_t GiB = 1024 * 1024 * 1024;
+    static const uint64_t nMinDiskSpace =
+        MIN_DISK_SPACE_FOR_BLOCK_FILES / GiB +
+                (MIN_DISK_SPACE_FOR_BLOCK_FILES % GiB)
+            ? 1
+            : 0;
+    ui->pruneSize->setMinimum(nMinDiskSpace);
     ui->threadsScriptVerif->setMinimum(-GetNumCores());
     ui->threadsScriptVerif->setMaximum(MAX_SCRIPTCHECK_THREADS);
+    ui->pruneWarning->setVisible(false);
+    ui->pruneWarning->setStyleSheet("QLabel { color: red; }");
+
+    ui->pruneSize->setEnabled(false);
+    connect(ui->prune, SIGNAL(toggled(bool)), ui->pruneSize,
+            SLOT(setEnabled(bool)));
 
 /* Network elements init */
 #ifndef USE_UPNP
     ui->mapPortUpnp->setEnabled(false);
 #endif
 
     ui->proxyIp->setEnabled(false);
     ui->proxyPort->setEnabled(false);
     ui->proxyPort->setValidator(new QIntValidator(1, 65535, this));
 
     ui->proxyIpTor->setEnabled(false);
     ui->proxyPortTor->setEnabled(false);
     ui->proxyPortTor->setValidator(new QIntValidator(1, 65535, this));
 
     connect(ui->connectSocks, SIGNAL(toggled(bool)), ui->proxyIp,
             SLOT(setEnabled(bool)));
     connect(ui->connectSocks, SIGNAL(toggled(bool)), ui->proxyPort,
             SLOT(setEnabled(bool)));
     connect(ui->connectSocks, SIGNAL(toggled(bool)), this,
             SLOT(updateProxyValidationState()));
 
     connect(ui->connectSocksTor, SIGNAL(toggled(bool)), ui->proxyIpTor,
             SLOT(setEnabled(bool)));
     connect(ui->connectSocksTor, SIGNAL(toggled(bool)), ui->proxyPortTor,
             SLOT(setEnabled(bool)));
     connect(ui->connectSocksTor, SIGNAL(toggled(bool)), this,
             SLOT(updateProxyValidationState()));
 
 /* Window elements init */
 #ifdef Q_OS_MAC
     /* remove Window tab on Mac */
     ui->tabWidget->removeTab(ui->tabWidget->indexOf(ui->tabWindow));
 #endif
 
     /* remove Wallet tab in case of -disablewallet */
     if (!enableWallet) {
         ui->tabWidget->removeTab(ui->tabWidget->indexOf(ui->tabWallet));
     }
 
     /* Display elements init */
     QDir translations(":translations");
 
     ui->bitcoinAtStartup->setToolTip(
         ui->bitcoinAtStartup->toolTip().arg(tr(PACKAGE_NAME)));
     ui->bitcoinAtStartup->setText(
         ui->bitcoinAtStartup->text().arg(tr(PACKAGE_NAME)));
 
     ui->openBitcoinConfButton->setToolTip(
         ui->openBitcoinConfButton->toolTip().arg(tr(PACKAGE_NAME)));
 
     ui->lang->setToolTip(ui->lang->toolTip().arg(tr(PACKAGE_NAME)));
     ui->lang->addItem(QString("(") + tr("default") + QString(")"),
                       QVariant(""));
     for (const QString &langStr : translations.entryList()) {
         QLocale locale(langStr);
 
         /** check if the locale name consists of 2 parts (language_country) */
         if (langStr.contains("_")) {
             /** display language strings as "native language - native country
              * (locale name)", e.g. "Deutsch - Deutschland (de)" */
             ui->lang->addItem(locale.nativeLanguageName() + QString(" - ") +
                                   locale.nativeCountryName() + QString(" (") +
                                   langStr + QString(")"),
                               QVariant(langStr));
         } else {
             /** display language strings as "native language (locale name)",
              * e.g. "Deutsch (de)" */
             ui->lang->addItem(locale.nativeLanguageName() + QString(" (") +
                                   langStr + QString(")"),
                               QVariant(langStr));
         }
     }
     ui->thirdPartyTxUrls->setPlaceholderText("https://example.com/tx/%s");
 
     ui->unit->setModel(new BitcoinUnits(this));
 
     /* Widget-to-option mapper */
     mapper = new QDataWidgetMapper(this);
     mapper->setSubmitPolicy(QDataWidgetMapper::ManualSubmit);
     mapper->setOrientation(Qt::Vertical);
 
     /* setup/change UI elements when proxy IPs are invalid/valid */
     ui->proxyIp->setCheckValidator(new ProxyAddressValidator(parent));
     ui->proxyIpTor->setCheckValidator(new ProxyAddressValidator(parent));
     connect(ui->proxyIp, SIGNAL(validationDidChange(QValidatedLineEdit *)),
             this, SLOT(updateProxyValidationState()));
     connect(ui->proxyIpTor, SIGNAL(validationDidChange(QValidatedLineEdit *)),
             this, SLOT(updateProxyValidationState()));
     connect(ui->proxyPort, SIGNAL(textChanged(const QString &)), this,
             SLOT(updateProxyValidationState()));
     connect(ui->proxyPortTor, SIGNAL(textChanged(const QString &)), this,
             SLOT(updateProxyValidationState()));
 }
 
 OptionsDialog::~OptionsDialog() {
     delete ui;
 }
 
 void OptionsDialog::setModel(OptionsModel *_model) {
     this->model = _model;
 
     if (_model) {
         /* check if client restart is needed and show persistent message */
         if (_model->isRestartRequired()) showRestartWarning(true);
 
         QString strLabel = _model->getOverriddenByCommandLine();
         if (strLabel.isEmpty()) strLabel = tr("none");
         ui->overriddenByCommandLineLabel->setText(strLabel);
 
         mapper->setModel(_model);
         setMapper();
         mapper->toFirst();
 
         updateDefaultProxyNets();
     }
 
     /* warn when one of the following settings changes by user action (placed
      * here so init via mapper doesn't trigger them) */
 
     /* Main */
+    connect(ui->prune, SIGNAL(clicked(bool)), this, SLOT(showRestartWarning()));
+    connect(ui->prune, SIGNAL(clicked(bool)), this,
+            SLOT(togglePruneWarning(bool)));
+    connect(ui->pruneSize, SIGNAL(valueChanged(int)), this,
+            SLOT(showRestartWarning()));
     connect(ui->databaseCache, SIGNAL(valueChanged(int)), this,
             SLOT(showRestartWarning()));
     connect(ui->threadsScriptVerif, SIGNAL(valueChanged(int)), this,
             SLOT(showRestartWarning()));
     /* Wallet */
     connect(ui->spendZeroConfChange, SIGNAL(clicked(bool)), this,
             SLOT(showRestartWarning()));
     /* Network */
     connect(ui->allowIncoming, SIGNAL(clicked(bool)), this,
             SLOT(showRestartWarning()));
     connect(ui->connectSocks, SIGNAL(clicked(bool)), this,
             SLOT(showRestartWarning()));
     connect(ui->connectSocksTor, SIGNAL(clicked(bool)), this,
             SLOT(showRestartWarning()));
     /* Display */
     connect(ui->lang, SIGNAL(valueChanged()), this, SLOT(showRestartWarning()));
     connect(ui->thirdPartyTxUrls, SIGNAL(textChanged(const QString &)), this,
             SLOT(showRestartWarning()));
 }
 
 void OptionsDialog::setMapper() {
     /* Main */
     mapper->addMapping(ui->bitcoinAtStartup, OptionsModel::StartAtStartup);
     mapper->addMapping(ui->threadsScriptVerif,
                        OptionsModel::ThreadsScriptVerif);
     mapper->addMapping(ui->databaseCache, OptionsModel::DatabaseCache);
+    mapper->addMapping(ui->prune, OptionsModel::Prune);
+    mapper->addMapping(ui->pruneSize, OptionsModel::PruneSize);
 
     /* Wallet */
     mapper->addMapping(ui->spendZeroConfChange,
                        OptionsModel::SpendZeroConfChange);
     mapper->addMapping(ui->coinControlFeatures,
                        OptionsModel::CoinControlFeatures);
 
     /* Network */
     mapper->addMapping(ui->mapPortUpnp, OptionsModel::MapPortUPnP);
     mapper->addMapping(ui->allowIncoming, OptionsModel::Listen);
 
     mapper->addMapping(ui->connectSocks, OptionsModel::ProxyUse);
     mapper->addMapping(ui->proxyIp, OptionsModel::ProxyIP);
     mapper->addMapping(ui->proxyPort, OptionsModel::ProxyPort);
 
     mapper->addMapping(ui->connectSocksTor, OptionsModel::ProxyUseTor);
     mapper->addMapping(ui->proxyIpTor, OptionsModel::ProxyIPTor);
     mapper->addMapping(ui->proxyPortTor, OptionsModel::ProxyPortTor);
 
 /* Window */
 #ifndef Q_OS_MAC
     mapper->addMapping(ui->hideTrayIcon, OptionsModel::HideTrayIcon);
     mapper->addMapping(ui->minimizeToTray, OptionsModel::MinimizeToTray);
     mapper->addMapping(ui->minimizeOnClose, OptionsModel::MinimizeOnClose);
 #endif
 
     /* Display */
     mapper->addMapping(ui->lang, OptionsModel::Language);
     mapper->addMapping(ui->unit, OptionsModel::DisplayUnit);
     mapper->addMapping(ui->thirdPartyTxUrls, OptionsModel::ThirdPartyTxUrls);
 }
 
 void OptionsDialog::setOkButtonState(bool fState) {
     ui->okButton->setEnabled(fState);
 }
 
 void OptionsDialog::on_resetButton_clicked() {
     if (model) {
         // confirmation dialog
         QMessageBox::StandardButton btnRetVal = QMessageBox::question(
             this, tr("Confirm options reset"),
             tr("Client restart required to activate changes.") + "<br><br>" +
                 tr("Client will be shut down. Do you want to proceed?"),
             QMessageBox::Yes | QMessageBox::Cancel, QMessageBox::Cancel);
 
         if (btnRetVal == QMessageBox::Cancel) return;
 
         /* reset all options and close GUI */
         model->Reset();
         QApplication::quit();
     }
 }
 
 void OptionsDialog::on_openBitcoinConfButton_clicked() {
     /* explain the purpose of the config file */
     QMessageBox::information(
         this, tr("Configuration options"),
         tr("The configuration file is used to specify advanced user options "
            "which override GUI settings. Additionally, any command-line "
            "options will override this configuration file."));
 
     /* show an error if there was some problem opening the file */
     if (!GUIUtil::openBitcoinConf()) {
         QMessageBox::critical(
             this, tr("Error"),
             tr("The configuration file could not be opened."));
     }
 }
 
 void OptionsDialog::on_okButton_clicked() {
     mapper->submit();
     accept();
     updateDefaultProxyNets();
 }
 
 void OptionsDialog::on_cancelButton_clicked() {
     reject();
 }
 
 void OptionsDialog::on_hideTrayIcon_stateChanged(int fState) {
     if (fState) {
         ui->minimizeToTray->setChecked(false);
         ui->minimizeToTray->setEnabled(false);
     } else {
         ui->minimizeToTray->setEnabled(true);
     }
 }
 
+void OptionsDialog::togglePruneWarning(bool enabled) {
+    ui->pruneWarning->setVisible(!ui->pruneWarning->isVisible());
+}
+
 void OptionsDialog::showRestartWarning(bool fPersistent) {
     ui->statusLabel->setStyleSheet("QLabel { color: red; }");
 
     if (fPersistent) {
         ui->statusLabel->setText(
             tr("Client restart required to activate changes."));
     } else {
         ui->statusLabel->setText(
             tr("This change would require a client restart."));
         // clear non-persistent status label after 10 seconds
         // TODO: should perhaps be a class attribute, if we extend the use of
         // statusLabel
         QTimer::singleShot(10000, this, SLOT(clearStatusLabel()));
     }
 }
 
 void OptionsDialog::clearStatusLabel() {
     ui->statusLabel->clear();
     if (model && model->isRestartRequired()) {
         showRestartWarning(true);
     }
 }
 
 void OptionsDialog::updateProxyValidationState() {
     QValidatedLineEdit *pUiProxyIp = ui->proxyIp;
     QValidatedLineEdit *otherProxyWidget =
         (pUiProxyIp == ui->proxyIpTor) ? ui->proxyIp : ui->proxyIpTor;
     if (pUiProxyIp->isValid() &&
         (!ui->proxyPort->isEnabled() || ui->proxyPort->text().toInt() > 0) &&
         (!ui->proxyPortTor->isEnabled() ||
          ui->proxyPortTor->text().toInt() > 0)) {
         // Only enable ok button if both proxys are valid
         setOkButtonState(otherProxyWidget->isValid());
         clearStatusLabel();
     } else {
         setOkButtonState(false);
         ui->statusLabel->setStyleSheet("QLabel { color: red; }");
         ui->statusLabel->setText(tr("The supplied proxy address is invalid."));
     }
 }
 
 void OptionsDialog::updateDefaultProxyNets() {
     proxyType proxy;
     std::string strProxy;
     QString strDefaultProxyGUI;
 
     model->node().getProxy(NET_IPV4, proxy);
     strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
     strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
     (strProxy == strDefaultProxyGUI.toStdString())
         ? ui->proxyReachIPv4->setChecked(true)
         : ui->proxyReachIPv4->setChecked(false);
 
     model->node().getProxy(NET_IPV6, proxy);
     strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
     strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
     (strProxy == strDefaultProxyGUI.toStdString())
         ? ui->proxyReachIPv6->setChecked(true)
         : ui->proxyReachIPv6->setChecked(false);
 
     model->node().getProxy(NET_ONION, proxy);
     strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
     strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
     (strProxy == strDefaultProxyGUI.toStdString())
         ? ui->proxyReachTor->setChecked(true)
         : ui->proxyReachTor->setChecked(false);
 }
 
 ProxyAddressValidator::ProxyAddressValidator(QObject *parent)
     : QValidator(parent) {}
 
 QValidator::State ProxyAddressValidator::validate(QString &input,
                                                   int &pos) const {
     Q_UNUSED(pos);
     // Validate the proxy
     CService serv(
         LookupNumeric(input.toStdString().c_str(), DEFAULT_GUI_PROXY_PORT));
     proxyType addrProxy = proxyType(serv, true);
     if (addrProxy.IsValid()) return QValidator::Acceptable;
 
     return QValidator::Invalid;
 }
diff --git a/src/qt/optionsdialog.h b/src/qt/optionsdialog.h
index 10a37205f..87361ff65 100644
--- a/src/qt/optionsdialog.h
+++ b/src/qt/optionsdialog.h
@@ -1,68 +1,69 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_QT_OPTIONSDIALOG_H
 #define BITCOIN_QT_OPTIONSDIALOG_H
 
 #include <QDialog>
 #include <QValidator>
 
 class OptionsModel;
 class QValidatedLineEdit;
 
 QT_BEGIN_NAMESPACE
 class QDataWidgetMapper;
 QT_END_NAMESPACE
 
 namespace Ui {
 class OptionsDialog;
 }
 
 /** Proxy address widget validator, checks for a valid proxy address. */
 class ProxyAddressValidator : public QValidator {
     Q_OBJECT
 
 public:
     explicit ProxyAddressValidator(QObject *parent);
 
     State validate(QString &input, int &pos) const override;
 };
 
 /** Preferences dialog. */
 class OptionsDialog : public QDialog {
     Q_OBJECT
 
 public:
     explicit OptionsDialog(QWidget *parent, bool enableWallet);
     ~OptionsDialog();
 
     void setModel(OptionsModel *model);
     void setMapper();
 
 private Q_SLOTS:
     /* set OK button state (enabled / disabled) */
     void setOkButtonState(bool fState);
     void on_resetButton_clicked();
     void on_openBitcoinConfButton_clicked();
     void on_okButton_clicked();
     void on_cancelButton_clicked();
 
     void on_hideTrayIcon_stateChanged(int fState);
 
+    void togglePruneWarning(bool enabled);
     void showRestartWarning(bool fPersistent = false);
     void clearStatusLabel();
     void updateProxyValidationState();
     /* query the networks, for which the default proxy is used */
     void updateDefaultProxyNets();
 
 Q_SIGNALS:
     void proxyIpChecks(QValidatedLineEdit *pUiProxyIp, int nProxyPort);
 
 private:
     Ui::OptionsDialog *ui;
     OptionsModel *model;
     QDataWidgetMapper *mapper;
 };
 
 #endif // BITCOIN_QT_OPTIONSDIALOG_H
diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp
index 85d34b6d9..39a3eb312 100644
--- a/src/qt/optionsmodel.cpp
+++ b/src/qt/optionsmodel.cpp
@@ -1,545 +1,575 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #if defined(HAVE_CONFIG_H)
 #include <config/bitcoin-config.h>
 #endif
 
 #include <qt/optionsmodel.h>
 
 #include <amount.h>
 #include <interfaces/node.h>
 #include <net.h>
 #include <netbase.h>
 #include <qt/bitcoinunits.h>
 #include <qt/guiutil.h>
 #include <qt/intro.h>
 #include <txdb.h>       // for -dbcache defaults
 #include <validation.h> // For DEFAULT_SCRIPTCHECK_THREADS
 
 #include <QNetworkProxy>
 #include <QSettings>
 #include <QStringList>
 
 const char *DEFAULT_GUI_PROXY_HOST = "127.0.0.1";
 
 static const QString GetDefaultProxyAddress();
 
 OptionsModel::OptionsModel(interfaces::Node &node, QObject *parent,
                            bool resetSettings)
     : QAbstractListModel(parent), m_node(node) {
     Init(resetSettings);
 }
 
 void OptionsModel::addOverriddenOption(const std::string &option) {
     strOverriddenByCommandLine +=
         QString::fromStdString(option) + "=" +
         QString::fromStdString(gArgs.GetArg(option, "")) + " ";
 }
 
 // Writes all missing QSettings with their default values
 void OptionsModel::Init(bool resetSettings) {
     if (resetSettings) {
         Reset();
     }
 
     checkAndMigrate();
 
     QSettings settings;
 
     // Ensure restart flag is unset on client startup
     setRestartRequired(false);
 
     // These are Qt-only settings:
 
     // Window
     if (!settings.contains("fHideTrayIcon")) {
         settings.setValue("fHideTrayIcon", false);
     }
     fHideTrayIcon = settings.value("fHideTrayIcon").toBool();
     Q_EMIT hideTrayIconChanged(fHideTrayIcon);
 
     if (!settings.contains("fMinimizeToTray")) {
         settings.setValue("fMinimizeToTray", false);
     }
     fMinimizeToTray =
         settings.value("fMinimizeToTray").toBool() && !fHideTrayIcon;
 
     if (!settings.contains("fMinimizeOnClose")) {
         settings.setValue("fMinimizeOnClose", false);
     }
     fMinimizeOnClose = settings.value("fMinimizeOnClose").toBool();
 
     // Display
     if (!settings.contains("nDisplayUnit")) {
         settings.setValue("nDisplayUnit", BitcoinUnits::BCH);
     }
     nDisplayUnit = settings.value("nDisplayUnit").toInt();
 
     if (!settings.contains("strThirdPartyTxUrls")) {
         settings.setValue("strThirdPartyTxUrls", "");
     }
     strThirdPartyTxUrls = settings.value("strThirdPartyTxUrls", "").toString();
 
     if (!settings.contains("fCoinControlFeatures")) {
         settings.setValue("fCoinControlFeatures", false);
     }
     fCoinControlFeatures =
         settings.value("fCoinControlFeatures", false).toBool();
 
     // These are shared with the core or have a command-line parameter
     // and we want command-line parameters to overwrite the GUI settings.
     //
     // If setting doesn't exist create it with defaults.
     //
     // If gArgs.SoftSetArg() or gArgs.SoftSetBoolArg() return false we were
     // overridden
     // by command-line and show this in the UI.
 
     // Main
+    if (!settings.contains("bPrune")) {
+        settings.setValue("bPrune", false);
+    }
+    if (!settings.contains("nPruneSize")) {
+        settings.setValue("nPruneSize", 2);
+    }
+    // Convert prune size to MB:
+    const uint64_t nPruneSizeMB = settings.value("nPruneSize").toInt() * 1000;
+    if (!m_node.softSetArg("-prune", settings.value("bPrune").toBool()
+                                         ? std::to_string(nPruneSizeMB)
+                                         : "0")) {
+        addOverriddenOption("-prune");
+    }
+
     if (!settings.contains("nDatabaseCache")) {
         settings.setValue("nDatabaseCache", (qint64)nDefaultDbCache);
     }
     if (!m_node.softSetArg(
             "-dbcache",
             settings.value("nDatabaseCache").toString().toStdString())) {
         addOverriddenOption("-dbcache");
     }
 
     if (!settings.contains("nThreadsScriptVerif")) {
         settings.setValue("nThreadsScriptVerif", DEFAULT_SCRIPTCHECK_THREADS);
     }
     if (!m_node.softSetArg(
             "-par",
             settings.value("nThreadsScriptVerif").toString().toStdString())) {
         addOverriddenOption("-par");
     }
 
     if (!settings.contains("strDataDir")) {
         settings.setValue("strDataDir", Intro::getDefaultDataDirectory());
     }
 
 // Wallet
 #ifdef ENABLE_WALLET
     if (!settings.contains("bSpendZeroConfChange")) {
         settings.setValue("bSpendZeroConfChange", true);
     }
     if (!m_node.softSetBoolArg(
             "-spendzeroconfchange",
             settings.value("bSpendZeroConfChange").toBool())) {
         addOverriddenOption("-spendzeroconfchange");
     }
 #endif
 
     // Network
     if (!settings.contains("fUseUPnP")) {
         settings.setValue("fUseUPnP", DEFAULT_UPNP);
     }
     if (!m_node.softSetBoolArg("-upnp", settings.value("fUseUPnP").toBool())) {
         addOverriddenOption("-upnp");
     }
 
     if (!settings.contains("fListen")) {
         settings.setValue("fListen", DEFAULT_LISTEN);
     }
     if (!m_node.softSetBoolArg("-listen", settings.value("fListen").toBool())) {
         addOverriddenOption("-listen");
     }
 
     if (!settings.contains("fUseProxy")) {
         settings.setValue("fUseProxy", false);
     }
     if (!settings.contains("addrProxy")) {
         settings.setValue("addrProxy", GetDefaultProxyAddress());
     }
     // Only try to set -proxy, if user has enabled fUseProxy
     if (settings.value("fUseProxy").toBool() &&
         !m_node.softSetArg(
             "-proxy", settings.value("addrProxy").toString().toStdString())) {
         addOverriddenOption("-proxy");
     } else if (!settings.value("fUseProxy").toBool() &&
                !gArgs.GetArg("-proxy", "").empty()) {
         addOverriddenOption("-proxy");
     }
 
     if (!settings.contains("fUseSeparateProxyTor")) {
         settings.setValue("fUseSeparateProxyTor", false);
     }
     if (!settings.contains("addrSeparateProxyTor")) {
         settings.setValue("addrSeparateProxyTor", GetDefaultProxyAddress());
     }
     // Only try to set -onion, if user has enabled fUseSeparateProxyTor
     if (settings.value("fUseSeparateProxyTor").toBool() &&
         !m_node.softSetArg(
             "-onion",
             settings.value("addrSeparateProxyTor").toString().toStdString())) {
         addOverriddenOption("-onion");
     } else if (!settings.value("fUseSeparateProxyTor").toBool() &&
                !gArgs.GetArg("-onion", "").empty()) {
         addOverriddenOption("-onion");
     }
 
     // Display
     if (!settings.contains("language")) {
         settings.setValue("language", "");
     }
     if (!m_node.softSetArg(
             "-lang", settings.value("language").toString().toStdString())) {
         addOverriddenOption("-lang");
     }
 
     language = settings.value("language").toString();
 }
 
 /**
  * Helper function to copy contents from one QSettings to another.
  * By using allKeys this also covers nested settings in a hierarchy.
  */
 static void CopySettings(QSettings &dst, const QSettings &src) {
     for (const QString &key : src.allKeys()) {
         dst.setValue(key, src.value(key));
     }
 }
 
 /** Back up a QSettings to an ini-formatted file. */
 static void BackupSettings(const fs::path &filename, const QSettings &src) {
     qWarning() << "Backing up GUI settings to"
                << GUIUtil::boostPathToQString(filename);
     QSettings dst(GUIUtil::boostPathToQString(filename), QSettings::IniFormat);
     dst.clear();
     CopySettings(dst, src);
 }
 
 void OptionsModel::Reset() {
     QSettings settings;
 
     // Backup old settings to chain-specific datadir for troubleshooting
     BackupSettings(GetDataDir(true) / "guisettings.ini.bak", settings);
 
     // Save the strDataDir setting
     QString dataDir = Intro::getDefaultDataDirectory();
     dataDir = settings.value("strDataDir", dataDir).toString();
 
     // Remove all entries from our QSettings object
     settings.clear();
 
     // Set strDataDir
     settings.setValue("strDataDir", dataDir);
 
     // Set that this was reset
     settings.setValue("fReset", true);
 
     // default setting for OptionsModel::StartAtStartup - disabled
     if (GUIUtil::GetStartOnSystemStartup()) {
         GUIUtil::SetStartOnSystemStartup(false);
     }
 }
 
 int OptionsModel::rowCount(const QModelIndex &parent) const {
     return OptionIDRowCount;
 }
 
 struct ProxySetting {
     bool is_set;
     QString ip;
     QString port;
 };
 
 static ProxySetting GetProxySetting(QSettings &settings, const QString &name) {
     static const ProxySetting default_val = {
         false, DEFAULT_GUI_PROXY_HOST,
         QString("%1").arg(DEFAULT_GUI_PROXY_PORT)};
     // Handle the case that the setting is not set at all
     if (!settings.contains(name)) {
         return default_val;
     }
     // contains IP at index 0 and port at index 1
     QStringList ip_port =
         settings.value(name).toString().split(":", QString::SkipEmptyParts);
     if (ip_port.size() == 2) {
         return {true, ip_port.at(0), ip_port.at(1)};
     } else { // Invalid: return default
         return default_val;
     }
 }
 
 static void SetProxySetting(QSettings &settings, const QString &name,
                             const ProxySetting &ip_port) {
     settings.setValue(name, ip_port.ip + ":" + ip_port.port);
 }
 
 static const QString GetDefaultProxyAddress() {
     return QString("%1:%2")
         .arg(DEFAULT_GUI_PROXY_HOST)
         .arg(DEFAULT_GUI_PROXY_PORT);
 }
 
 // read QSettings values and return them
 QVariant OptionsModel::data(const QModelIndex &index, int role) const {
     if (role == Qt::EditRole) {
         QSettings settings;
         switch (index.row()) {
             case StartAtStartup:
                 return GUIUtil::GetStartOnSystemStartup();
             case HideTrayIcon:
                 return fHideTrayIcon;
             case MinimizeToTray:
                 return fMinimizeToTray;
             case MapPortUPnP:
 #ifdef USE_UPNP
                 return settings.value("fUseUPnP");
 #else
                 return false;
 #endif
             case MinimizeOnClose:
                 return fMinimizeOnClose;
 
             // default proxy
             case ProxyUse:
                 return settings.value("fUseProxy", false);
             case ProxyIP:
                 return GetProxySetting(settings, "addrProxy").ip;
             case ProxyPort:
                 return GetProxySetting(settings, "addrProxy").port;
 
             // separate Tor proxy
             case ProxyUseTor:
                 return settings.value("fUseSeparateProxyTor", false);
             case ProxyIPTor:
                 return GetProxySetting(settings, "addrSeparateProxyTor").ip;
             case ProxyPortTor:
                 return GetProxySetting(settings, "addrSeparateProxyTor").port;
 
 #ifdef ENABLE_WALLET
             case SpendZeroConfChange:
                 return settings.value("bSpendZeroConfChange");
 #endif
             case DisplayUnit:
                 return nDisplayUnit;
             case ThirdPartyTxUrls:
                 return strThirdPartyTxUrls;
             case Language:
                 return settings.value("language");
             case CoinControlFeatures:
                 return fCoinControlFeatures;
+            case Prune:
+                return settings.value("bPrune");
+            case PruneSize:
+                return settings.value("nPruneSize");
             case DatabaseCache:
                 return settings.value("nDatabaseCache");
             case ThreadsScriptVerif:
                 return settings.value("nThreadsScriptVerif");
             case Listen:
                 return settings.value("fListen");
             default:
                 return QVariant();
         }
     }
     return QVariant();
 }
 
 // write QSettings values
 bool OptionsModel::setData(const QModelIndex &index, const QVariant &value,
                            int role) {
     bool successful = true; /* set to false on parse error */
     if (role == Qt::EditRole) {
         QSettings settings;
         switch (index.row()) {
             case StartAtStartup:
                 successful = GUIUtil::SetStartOnSystemStartup(value.toBool());
                 break;
             case HideTrayIcon:
                 fHideTrayIcon = value.toBool();
                 settings.setValue("fHideTrayIcon", fHideTrayIcon);
                 Q_EMIT hideTrayIconChanged(fHideTrayIcon);
                 break;
             case MinimizeToTray:
                 fMinimizeToTray = value.toBool();
                 settings.setValue("fMinimizeToTray", fMinimizeToTray);
                 break;
             case MapPortUPnP: // core option - can be changed on-the-fly
                 settings.setValue("fUseUPnP", value.toBool());
                 m_node.mapPort(value.toBool());
                 break;
             case MinimizeOnClose:
                 fMinimizeOnClose = value.toBool();
                 settings.setValue("fMinimizeOnClose", fMinimizeOnClose);
                 break;
 
             // default proxy
             case ProxyUse:
                 if (settings.value("fUseProxy") != value) {
                     settings.setValue("fUseProxy", value.toBool());
                     setRestartRequired(true);
                 }
                 break;
             case ProxyIP: {
                 auto ip_port = GetProxySetting(settings, "addrProxy");
                 if (!ip_port.is_set || ip_port.ip != value.toString()) {
                     ip_port.ip = value.toString();
                     SetProxySetting(settings, "addrProxy", ip_port);
                     setRestartRequired(true);
                 }
             } break;
             case ProxyPort: {
                 auto ip_port = GetProxySetting(settings, "addrProxy");
                 if (!ip_port.is_set || ip_port.port != value.toString()) {
                     ip_port.port = value.toString();
                     SetProxySetting(settings, "addrProxy", ip_port);
                     setRestartRequired(true);
                 }
             } break;
 
             // separate Tor proxy
             case ProxyUseTor:
                 if (settings.value("fUseSeparateProxyTor") != value) {
                     settings.setValue("fUseSeparateProxyTor", value.toBool());
                     setRestartRequired(true);
                 }
                 break;
             case ProxyIPTor: {
                 auto ip_port =
                     GetProxySetting(settings, "addrSeparateProxyTor");
                 if (!ip_port.is_set || ip_port.ip != value.toString()) {
                     ip_port.ip = value.toString();
                     SetProxySetting(settings, "addrSeparateProxyTor", ip_port);
                     setRestartRequired(true);
                 }
             } break;
             case ProxyPortTor: {
                 auto ip_port =
                     GetProxySetting(settings, "addrSeparateProxyTor");
                 if (!ip_port.is_set || ip_port.port != value.toString()) {
                     ip_port.port = value.toString();
                     SetProxySetting(settings, "addrSeparateProxyTor", ip_port);
                     setRestartRequired(true);
                 }
             } break;
 
 #ifdef ENABLE_WALLET
             case SpendZeroConfChange:
                 if (settings.value("bSpendZeroConfChange") != value) {
                     settings.setValue("bSpendZeroConfChange", value);
                     setRestartRequired(true);
                 }
                 break;
 #endif
             case DisplayUnit:
                 setDisplayUnit(value);
                 break;
             case ThirdPartyTxUrls:
                 if (strThirdPartyTxUrls != value.toString()) {
                     strThirdPartyTxUrls = value.toString();
                     settings.setValue("strThirdPartyTxUrls",
                                       strThirdPartyTxUrls);
                     setRestartRequired(true);
                 }
                 break;
             case Language:
                 if (settings.value("language") != value) {
                     settings.setValue("language", value);
                     setRestartRequired(true);
                 }
                 break;
             case CoinControlFeatures:
                 fCoinControlFeatures = value.toBool();
                 settings.setValue("fCoinControlFeatures", fCoinControlFeatures);
                 Q_EMIT coinControlFeaturesChanged(fCoinControlFeatures);
                 break;
+            case Prune:
+                if (settings.value("bPrune") != value) {
+                    settings.setValue("bPrune", value);
+                    setRestartRequired(true);
+                }
+                break;
+            case PruneSize:
+                if (settings.value("nPruneSize") != value) {
+                    settings.setValue("nPruneSize", value);
+                    setRestartRequired(true);
+                }
+                break;
             case DatabaseCache:
                 if (settings.value("nDatabaseCache") != value) {
                     settings.setValue("nDatabaseCache", value);
                     setRestartRequired(true);
                 }
                 break;
             case ThreadsScriptVerif:
                 if (settings.value("nThreadsScriptVerif") != value) {
                     settings.setValue("nThreadsScriptVerif", value);
                     setRestartRequired(true);
                 }
                 break;
             case Listen:
                 if (settings.value("fListen") != value) {
                     settings.setValue("fListen", value);
                     setRestartRequired(true);
                 }
                 break;
             default:
                 break;
         }
     }
 
     Q_EMIT dataChanged(index, index);
 
     return successful;
 }
 
 /** Updates current unit in memory, settings and emits
  * displayUnitChanged(newUnit) signal */
 void OptionsModel::setDisplayUnit(const QVariant &value) {
     if (!value.isNull()) {
         QSettings settings;
         nDisplayUnit = value.toInt();
         settings.setValue("nDisplayUnit", nDisplayUnit);
         Q_EMIT displayUnitChanged(nDisplayUnit);
     }
 }
 
 bool OptionsModel::getProxySettings(QNetworkProxy &proxy) const {
     // Directly query current base proxy, because
     // GUI settings can be overridden with -proxy.
     proxyType curProxy;
     if (m_node.getProxy(NET_IPV4, curProxy)) {
         proxy.setType(QNetworkProxy::Socks5Proxy);
         proxy.setHostName(QString::fromStdString(curProxy.proxy.ToStringIP()));
         proxy.setPort(curProxy.proxy.GetPort());
 
         return true;
     } else
         proxy.setType(QNetworkProxy::NoProxy);
 
     return false;
 }
 
 void OptionsModel::setRestartRequired(bool fRequired) {
     QSettings settings;
     return settings.setValue("fRestartRequired", fRequired);
 }
 
 bool OptionsModel::isRestartRequired() const {
     QSettings settings;
     return settings.value("fRestartRequired", false).toBool();
 }
 
 void OptionsModel::checkAndMigrate() {
     // Migration of default values
     // Check if the QSettings container was already loaded with this client
     // version
     QSettings settings;
     static const char strSettingsVersionKey[] = "nSettingsVersion";
     int settingsVersion = settings.contains(strSettingsVersionKey)
                               ? settings.value(strSettingsVersionKey).toInt()
                               : 0;
     if (settingsVersion < CLIENT_VERSION) {
         // -dbcache was bumped from 100 to 300 in 0.13
         // see https://github.com/bitcoin/bitcoin/pull/8273
         // force people to upgrade to the new value if they are using 100MB
         if (settingsVersion < 130000 && settings.contains("nDatabaseCache") &&
             settings.value("nDatabaseCache").toLongLong() == 100)
             settings.setValue("nDatabaseCache", (qint64)nDefaultDbCache);
 
         settings.setValue(strSettingsVersionKey, CLIENT_VERSION);
     }
 
     // Overwrite the 'addrProxy' setting in case it has been set to an illegal
     // default value (see issue #12623; PR #12650).
     if (settings.contains("addrProxy") &&
         settings.value("addrProxy").toString().endsWith("%2")) {
         settings.setValue("addrProxy", GetDefaultProxyAddress());
     }
 
     // Overwrite the 'addrSeparateProxyTor' setting in case it has been set to
     // an illegal default value (see issue #12623; PR #12650).
     if (settings.contains("addrSeparateProxyTor") &&
         settings.value("addrSeparateProxyTor").toString().endsWith("%2")) {
         settings.setValue("addrSeparateProxyTor", GetDefaultProxyAddress());
     }
 }
diff --git a/src/qt/optionsmodel.h b/src/qt/optionsmodel.h
index 266bfe1e0..9483be3d3 100644
--- a/src/qt/optionsmodel.h
+++ b/src/qt/optionsmodel.h
@@ -1,114 +1,116 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_QT_OPTIONSMODEL_H
 #define BITCOIN_QT_OPTIONSMODEL_H
 
 #include <amount.h>
 
 #include <QAbstractListModel>
 
 namespace interfaces {
 class Node;
 }
 
 QT_BEGIN_NAMESPACE
 class QNetworkProxy;
 QT_END_NAMESPACE
 
 extern const char *DEFAULT_GUI_PROXY_HOST;
 static constexpr unsigned short DEFAULT_GUI_PROXY_PORT = 9050;
 
 /** Interface from Qt to configuration data structure for Bitcoin client.
    To Qt, the options are presented as a list with the different options
    laid out vertically.
    This can be changed to a tree once the settings become sufficiently
    complex.
  */
 class OptionsModel : public QAbstractListModel {
     Q_OBJECT
 
 public:
     explicit OptionsModel(interfaces::Node &node, QObject *parent = 0,
                           bool resetSettings = false);
 
     enum OptionID {
         StartAtStartup,      // bool
         HideTrayIcon,        // bool
         MinimizeToTray,      // bool
         MapPortUPnP,         // bool
         MinimizeOnClose,     // bool
         ProxyUse,            // bool
         ProxyIP,             // QString
         ProxyPort,           // int
         ProxyUseTor,         // bool
         ProxyIPTor,          // QString
         ProxyPortTor,        // int
         DisplayUnit,         // BitcoinUnits::Unit
         ThirdPartyTxUrls,    // QString
         Language,            // QString
         CoinControlFeatures, // bool
         ThreadsScriptVerif,  // int
+        Prune,               // bool
+        PruneSize,           // int
         DatabaseCache,       // int
         SpendZeroConfChange, // bool
         Listen,              // bool
         OptionIDRowCount,
     };
 
     void Init(bool resetSettings = false);
     void Reset();
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     QVariant data(const QModelIndex &index,
                   int role = Qt::DisplayRole) const override;
     bool setData(const QModelIndex &index, const QVariant &value,
                  int role = Qt::EditRole) override;
     /** Updates current unit in memory, settings and emits
      * displayUnitChanged(newUnit) signal */
     void setDisplayUnit(const QVariant &value);
 
     /* Explicit getters */
     bool getHideTrayIcon() const { return fHideTrayIcon; }
     bool getMinimizeToTray() const { return fMinimizeToTray; }
     bool getMinimizeOnClose() const { return fMinimizeOnClose; }
     int getDisplayUnit() const { return nDisplayUnit; }
     QString getThirdPartyTxUrls() const { return strThirdPartyTxUrls; }
     bool getProxySettings(QNetworkProxy &proxy) const;
     bool getCoinControlFeatures() const { return fCoinControlFeatures; }
     const QString &getOverriddenByCommandLine() {
         return strOverriddenByCommandLine;
     }
 
     /* Restart flag helper */
     void setRestartRequired(bool fRequired);
     bool isRestartRequired() const;
 
     interfaces::Node &node() const { return m_node; }
 
 private:
     interfaces::Node &m_node;
     /* Qt-only settings */
     bool fHideTrayIcon;
     bool fMinimizeToTray;
     bool fMinimizeOnClose;
     QString language;
     int nDisplayUnit;
     QString strThirdPartyTxUrls;
     bool fCoinControlFeatures;
     /* settings that were overridden by command-line */
     QString strOverriddenByCommandLine;
 
     // Add option to list of GUI options overridden through command line/config
     // file
     void addOverriddenOption(const std::string &option);
 
     // Check settings version and upgrade default values if required
     void checkAndMigrate();
 Q_SIGNALS:
     void displayUnitChanged(int unit);
     void coinControlFeaturesChanged(bool);
     void hideTrayIconChanged(bool);
 };
 
 #endif // BITCOIN_QT_OPTIONSMODEL_H