diff --git a/src/plugins/platformthemes/gtk3/qgtk3interface.cpp b/src/plugins/platformthemes/gtk3/qgtk3interface.cpp
index 758a5095af9..5229cb73460 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3interface.cpp
+++ b/src/plugins/platformthemes/gtk3/qgtk3interface.cpp
@@ -475,15 +475,18 @@ QBrush QGtk3Interface::brush(QGtkWidget wtype, QGtkColorSource source, GtkStateF
     \internal
     \brief Returns the name of the current GTK theme.
  */
-const QString QGtk3Interface::themeName() const
+QString QGtk3Interface::themeName() const
 {
-    gchar *theme_name;
-    GtkSettings *settings = gtk_settings_get_default();
-    if (!settings)
-        return QString();
+    QString name;
 
-    g_object_get(settings, "gtk-theme-name", &theme_name, nullptr);
-    return QLatin1StringView(theme_name);
+    if (GtkSettings *settings = gtk_settings_get_default()) {
+        gchar *theme_name;
+        g_object_get(settings, "gtk-theme-name", &theme_name, nullptr);
+        name = QLatin1StringView(theme_name);
+        g_free(theme_name);
+    }
+
+    return name;
 }
 
 /*!
diff --git a/src/plugins/platformthemes/gtk3/qgtk3interface_p.h b/src/plugins/platformthemes/gtk3/qgtk3interface_p.h
index b92adcd7203..c43932a4fa3 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3interface_p.h
+++ b/src/plugins/platformthemes/gtk3/qgtk3interface_p.h
@@ -134,7 +134,7 @@ public:
     QIcon fileIcon(const QFileInfo &fileInfo) const;
 
     // Return current GTK theme name
-    const QString themeName() const;
+    QString themeName() const;
 
     // Derive color scheme from default colors
     Qt::ColorScheme colorSchemeByColors() const;