diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -554,6 +554,7 @@
 	node/context.cpp
 	node/psbt.cpp
 	node/transaction.cpp
+	node/ui_interface.cpp
 	noui.cpp
 	policy/fees.cpp
 	policy/settings.cpp
@@ -579,7 +580,6 @@
 	torcontrol.cpp
 	txdb.cpp
 	txmempool.cpp
-	ui_interface.cpp
 	validation.cpp
 	validationinterface.cpp
 	versionbits.cpp
diff --git a/src/banman.cpp b/src/banman.cpp
--- a/src/banman.cpp
+++ b/src/banman.cpp
@@ -6,7 +6,7 @@
 #include <banman.h>
 
 #include <netaddress.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <util/translation.h>
diff --git a/src/bitcoind.cpp b/src/bitcoind.cpp
--- a/src/bitcoind.cpp
+++ b/src/bitcoind.cpp
@@ -16,9 +16,9 @@
 #include <interfaces/chain.h>
 #include <network.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <noui.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <util/ref.h>
 #include <util/strencodings.h>
 #include <util/system.h>
diff --git a/src/httprpc.cpp b/src/httprpc.cpp
--- a/src/httprpc.cpp
+++ b/src/httprpc.cpp
@@ -7,8 +7,8 @@
 #include <chainparams.h>
 #include <config.h>
 #include <crypto/hmac_sha256.h>
+#include <node/ui_interface.h>
 #include <rpc/protocol.h>
-#include <ui_interface.h>
 #include <util/ref.h>
 #include <util/strencodings.h>
 #include <util/system.h>
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -10,10 +10,10 @@
 #include <config.h>
 #include <logging.h>
 #include <netbase.h>
+#include <node/ui_interface.h>
 #include <rpc/protocol.h> // For HTTP status codes
 #include <shutdown.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/threadnames.h>
diff --git a/src/index/base.cpp b/src/index/base.cpp
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -7,9 +7,9 @@
 #include <chainparams.h>
 #include <config.h>
 #include <index/base.h>
+#include <node/ui_interface.h>
 #include <shutdown.h>
 #include <tinyformat.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
@@ -25,10 +25,7 @@
     std::string strMessage = tfm::format(fmt, args...);
     SetMiscWarning(strMessage);
     LogPrintf("*** %s\n", strMessage);
-    uiInterface.ThreadSafeMessageBox(
-        Untranslated("Error: A fatal internal error occurred, see debug.log "
-                     "for details"),
-        "", CClientUIInterface::MSG_ERROR);
+    AbortError(_("A fatal internal error occurred, see debug.log for details"));
     StartShutdown();
 }
 
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -6,8 +6,8 @@
 
 #include <blockdb.h>
 #include <chain.h>
+#include <node/ui_interface.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -37,6 +37,7 @@
 #include <netbase.h>
 #include <network.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
@@ -53,7 +54,6 @@
 #include <torcontrol.h>
 #include <txdb.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <util/asmap.h>
 #include <util/check.h>
 #include <util/moneystr.h>
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -14,6 +14,7 @@
 #include <node/coin.h>
 #include <node/context.h>
 #include <node/transaction.h>
+#include <node/ui_interface.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
@@ -25,7 +26,6 @@
 #include <sync.h>
 #include <timedata.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <univalue.h>
 #include <util/system.h>
 #include <validation.h>
diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -18,6 +18,7 @@
 #include <netaddress.h>
 #include <netbase.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <policy/fees.h>
 #include <policy/settings.h>
 #include <primitives/block.h>
@@ -26,7 +27,6 @@
 #include <support/allocators/secure.h>
 #include <sync.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <util/ref.h>
 #include <util/system.h>
 #include <util/translation.h>
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -11,8 +11,8 @@
 #include <script/sighashtype.h>
 #include <script/standard.h>           // For CTxDestination
 #include <support/allocators/secure.h> // For SecureString
-#include <ui_interface.h>              // For ChangeType
 #include <util/message.h>
+#include <util/ui_change_type.h>
 
 #include <cstdint>
 #include <functional>
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -16,10 +16,10 @@
 #include <script/standard.h>
 #include <support/allocators/secure.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <util/check.h>
 #include <util/ref.h>
 #include <util/system.h>
+#include <util/ui_change_type.h>
 #include <wallet/context.h>
 #include <wallet/fees.h>
 #include <wallet/ismine.h>
diff --git a/src/net.cpp b/src/net.cpp
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -15,9 +15,9 @@
 #include <consensus/consensus.h>
 #include <crypto/sha256.h>
 #include <netbase.h>
+#include <node/ui_interface.h>
 #include <random.h>
 #include <scheduler.h>
-#include <ui_interface.h>
 #include <util/strencodings.h>
 #include <util/translation.h>
 
diff --git a/src/ui_interface.h b/src/node/ui_interface.h
rename from src/ui_interface.h
rename to src/node/ui_interface.h
--- a/src/ui_interface.h
+++ b/src/node/ui_interface.h
@@ -3,8 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UI_INTERFACE_H
-#define BITCOIN_UI_INTERFACE_H
+#ifndef BITCOIN_NODE_UI_INTERFACE_H
+#define BITCOIN_NODE_UI_INTERFACE_H
 
 #include <functional>
 #include <memory>
@@ -20,9 +20,6 @@
 }
 } // namespace boost
 
-/** General change type (added, updated, removed). */
-enum ChangeType { CT_NEW, CT_UPDATED, CT_DELETED };
-
 /** Signals for UI communication. */
 class CClientUIInterface {
 public:
@@ -141,7 +138,8 @@
 
 /** Show error message **/
 bool InitError(const bilingual_str &str);
+constexpr auto AbortError = InitError;
 
 extern CClientUIInterface uiInterface;
 
-#endif // BITCOIN_UI_INTERFACE_H
+#endif // BITCOIN_NODE_UI_INTERFACE_H
diff --git a/src/ui_interface.cpp b/src/node/ui_interface.cpp
rename from src/ui_interface.cpp
rename to src/node/ui_interface.cpp
--- a/src/ui_interface.cpp
+++ b/src/node/ui_interface.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 
 #include <util/translation.h>
 
diff --git a/src/noui.cpp b/src/noui.cpp
--- a/src/noui.cpp
+++ b/src/noui.cpp
@@ -6,7 +6,7 @@
 #include <noui.h>
 
 #include <logging.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <util/translation.h>
 
 #include <boost/signals2/connection.hpp>
@@ -23,20 +23,20 @@
     style &= ~CClientUIInterface::SECURE;
 
     std::string strCaption;
-        switch (style) {
-            case CClientUIInterface::MSG_ERROR:
-                strCaption = "Error: ";
-                break;
-            case CClientUIInterface::MSG_WARNING:
-                strCaption = "Warning: ";
-                break;
-            case CClientUIInterface::MSG_INFORMATION:
-                strCaption = "Information: ";
-                break;
-            default:
-                // Use supplied caption (can be empty)
-                strCaption = caption + ": ";
-        }
+    switch (style) {
+        case CClientUIInterface::MSG_ERROR:
+            strCaption = "Error: ";
+            break;
+        case CClientUIInterface::MSG_WARNING:
+            strCaption = "Warning: ";
+            break;
+        case CClientUIInterface::MSG_INFORMATION:
+            strCaption = "Information: ";
+            break;
+        default:
+            // Use supplied caption (can be empty)
+            strCaption = caption + ": ";
+    }
 
     if (!fSecure) {
         LogPrintf("%s%s\n", strCaption, message.original);
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -22,7 +22,6 @@
 #include <qt/splashscreen.h>
 #include <qt/utilitydialog.h>
 #include <qt/winshutdownmonitor.h>
-#include <ui_interface.h>
 #include <uint256.h>
 #include <util/ref.h>
 #include <util/system.h>
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -9,6 +9,7 @@
 #include <config.h>
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
+#include <node/ui_interface.h>
 #include <qt/bitcoinunits.h>
 #include <qt/clientmodel.h>
 #include <qt/createwalletdialog.h>
@@ -31,7 +32,6 @@
 #include <qt/walletmodel.h>
 #include <qt/walletview.h>
 #endif // ENABLE_WALLET
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -8,11 +8,11 @@
 #include <chainparams.h>
 #include <interfaces/node.h>
 #include <key_io.h>
+#include <node/ui_interface.h>
 #include <policy/policy.h>
 #include <qt/bitcoinunits.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <wallet/wallet.h>
 
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -12,6 +12,7 @@
 #include <chainparams.h>
 #include <interfaces/node.h>
 #include <key_io.h>
+#include <node/ui_interface.h>
 #include <qt/addresstablemodel.h>
 #include <qt/bitcoinunits.h>
 #include <qt/clientmodel.h>
@@ -21,7 +22,6 @@
 #include <qt/platformstyle.h>
 #include <qt/sendcoinsentry.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <wallet/coincontrol.h>
 #include <wallet/fees.h>
 #include <wallet/wallet.h>
diff --git a/src/qt/splashscreen.cpp b/src/qt/splashscreen.cpp
--- a/src/qt/splashscreen.cpp
+++ b/src/qt/splashscreen.cpp
@@ -14,7 +14,6 @@
 #include <interfaces/wallet.h>
 #include <qt/guiutil.h>
 #include <qt/networkstyle.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -4,6 +4,7 @@
 
 #include <qt/transactionview.h>
 
+#include <node/ui_interface.h>
 #include <qt/addresstablemodel.h>
 #include <qt/bitcoinunits.h>
 #include <qt/csvmodelwriter.h>
@@ -15,7 +16,6 @@
 #include <qt/transactionrecord.h>
 #include <qt/transactiontablemodel.h>
 #include <qt/walletmodel.h>
-#include <ui_interface.h>
 
 #include <QComboBox>
 #include <QDateTimeEdit>
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -8,13 +8,13 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <key_io.h>
+#include <node/ui_interface.h>
 #include <psbt.h>
 #include <qt/addresstablemodel.h>
 #include <qt/guiconstants.h>
 #include <qt/paymentserver.h>
 #include <qt/recentrequeststablemodel.h>
 #include <qt/transactiontablemodel.h>
-#include <ui_interface.h>
 #include <util/system.h> // for GetBoolArg
 #include <util/translation.h>
 #include <wallet/coincontrol.h>
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -8,6 +8,7 @@
 #include <interfaces/node.h>
 #include <node/psbt.h>
 #include <node/transaction.h>
+#include <node/ui_interface.h>
 #include <policy/policy.h>
 #include <qt/addressbookpage.h>
 #include <qt/askpassphrasedialog.h>
@@ -23,7 +24,6 @@
 #include <qt/transactiontablemodel.h>
 #include <qt/transactionview.h>
 #include <qt/walletmodel.h>
-#include <ui_interface.h>
 #include <util/strencodings.h>
 
 #include <QAction>
diff --git a/src/timedata.cpp b/src/timedata.cpp
--- a/src/timedata.cpp
+++ b/src/timedata.cpp
@@ -9,8 +9,8 @@
 #include <timedata.h>
 
 #include <netaddress.h>
+#include <node/ui_interface.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <warnings.h>
diff --git a/src/txdb.cpp b/src/txdb.cpp
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -7,10 +7,10 @@
 
 #include <blockdb.h>
 #include <chain.h>
+#include <node/ui_interface.h>
 #include <pow/pow.h>
 #include <random.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <util/vector.h>
diff --git a/src/util/ui_change_type.h b/src/util/ui_change_type.h
new file mode 100644
--- /dev/null
+++ b/src/util/ui_change_type.h
@@ -0,0 +1,11 @@
+// Copyright (c) 2012-2020 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_UTIL_UI_CHANGE_TYPE_H
+#define BITCOIN_UTIL_UI_CHANGE_TYPE_H
+
+/** General change type (added, updated, removed). */
+enum ChangeType { CT_NEW, CT_UPDATED, CT_DELETED };
+
+#endif // BITCOIN_UTIL_UI_CHANGE_TYPE_H
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -22,6 +22,7 @@
 #include <hash.h>
 #include <index/txindex.h>
 #include <minerfund.h>
+#include <node/ui_interface.h>
 #include <policy/fees.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
@@ -40,7 +41,6 @@
 #include <tinyformat.h>
 #include <txdb.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <undo.h>
 #include <util/check.h> // For NDEBUG compile time check
 #include <util/moneystr.h>
@@ -1288,8 +1288,6 @@
     return true;
 }
 
-constexpr auto AbortError = InitError;
-
 /** Abort with a message */
 static bool AbortNode(const std::string &strMessage,
                       bilingual_str user_message = bilingual_str()) {
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -10,7 +10,7 @@
 #include <net.h>
 #include <network.h>
 #include <node/context.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <util/check.h>
 #include <util/moneystr.h>
 #include <util/system.h>
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -14,11 +14,11 @@
 #include <primitives/blockhash.h>
 #include <psbt.h>
 #include <tinyformat.h>
-#include <ui_interface.h>
 #include <util/message.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/translation.h>
+#include <util/ui_change_type.h>
 #include <validationinterface.h>
 #include <wallet/coinselection.h>
 #include <wallet/crypter.h>