diff --git a/src/qt/guiconstants.h b/src/qt/guiconstants.h
--- a/src/qt/guiconstants.h
+++ b/src/qt/guiconstants.h
@@ -54,4 +54,7 @@
 #define QAPP_APP_NAME_TESTNET "BitcoinABC-Qt-testnet"
 #define QAPP_APP_NAME_REGTEST "BitcoinABC-Qt-regtest"
 
+/* One gigabyte (GB) in bytes */
+static constexpr uint64_t GB_BYTES{1000000000};
+
 #endif // BITCOIN_QT_GUICONSTANTS_H
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -11,7 +11,9 @@
 
 #include <interfaces/node.h>
 #include <netbase.h>
+
 #include <qt/bitcoinunits.h>
+#include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
 #include <txdb.h>       // for -dbcache defaults
@@ -33,13 +35,6 @@
     /* 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);
@@ -167,6 +162,14 @@
             showRestartWarning(true);
         }
 
+        // Prune values are in GB to be consistent with intro.cpp
+        static constexpr uint64_t nMinDiskSpace =
+            (MIN_DISK_SPACE_FOR_BLOCK_FILES / GB_BYTES) +
+                    (MIN_DISK_SPACE_FOR_BLOCK_FILES % GB_BYTES)
+                ? 1
+                : 0;
+        ui->pruneSize->setRange(nMinDiskSpace, std::numeric_limits<int>::max());
+
         QString strLabel = _model->getOverriddenByCommandLine();
         if (strLabel.isEmpty()) {
             strLabel = tr("none");