diff --git a/ui/qt/main_application.cpp b/ui/qt/main_application.cpp
index 306205a1f7..77188fe8e5 100644
--- a/ui/qt/main_application.cpp
+++ b/ui/qt/main_application.cpp
@@ -310,12 +310,28 @@ const QFont MainApplication::monospaceFont(bool zoomed) const
 void MainApplication::setMonospaceFont(const char *font_string) {
 
     if (font_string && strlen(font_string) > 0) {
-        mono_font_.fromString(font_string);
-
-        // Only accept the font name if it actually exists.
-        if (mono_font_.family() == QFontInfo(mono_font_).family()) {
-            return;
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
+        // Qt 6's QFont::toString returns a value with 16 fields, e.g.
+        // Consolas,11,-1,5,400,0,0,0,0,0,0,0,0,0,0,1
+        // Qt 5's QFont::fromString expects a value with 10 fields, e.g.
+        // Consolas,10,-1,5,50,0,0,0,0,0
+        const char *fs_ptr = font_string;
+        int comma_count = 0;
+        while ((fs_ptr = strchr(fs_ptr, ',')) != NULL) {
+            fs_ptr++;
+            comma_count++;
         }
+        if (comma_count < 10) {
+#endif
+            mono_font_.fromString(font_string);
+
+            // Only accept the font name if it actually exists.
+            if (mono_font_.family() == QFontInfo(mono_font_).family()) {
+                return;
+            }
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
+        }
+#endif
     }
 
     // https://en.wikipedia.org/wiki/Category:Monospaced_typefaces