diff --git a/ide/mainbar.pas b/ide/mainbar.pas
index 6cec9dc793..2d5214f0d4 100644
--- a/ide/mainbar.pas
+++ b/ide/mainbar.pas
@@ -511,7 +511,7 @@ begin
 end;
 
 function TMainIDEBar.CalcNonClientHeight: Integer;
-{$IF DEFINED(LCLGtk) OR DEFINED(LCLGtk2) OR DEFINED(LCLQt) OR DEFINED(LCLQt6)}
+{$IF DEFINED(LCLGtk) OR DEFINED(LCLQt) OR DEFINED(LCLQt6)}
 var
   WindowRect, WindowClientRect: TRect;
 {$ENDIF}
@@ -532,10 +532,10 @@ begin
   if not Showing then
     Exit(0);
 
-  {$IF DEFINED(LCLGtk) OR DEFINED(LCLGtk2) OR DEFINED(LCLQt) OR DEFINED(LCLQt6)}
-  //Gtk2 + Qt
+  {$IF DEFINED(LCLGtk) OR DEFINED(LCLQt) OR DEFINED(LCLQt6)}
+  //Gtk + Qt
   //retrieve real main menu height because
-  // - Gtk2, Qt:  SM_CYMENU does not work
+  // - Gtk, Qt:  SM_CYMENU does not work
   LclIntf.GetWindowRect(Handle, WindowRect{%H-});
   LclIntf.GetClientRect(Handle, WindowClientRect{%H-});
   LclIntf.ClientToScreen(Handle, WindowClientRect.TopLeft);
@@ -547,7 +547,10 @@ begin
   {$ELSE}
   //other widgetsets
   //Carbon tested - behaves correctly
+  //Cocoa tested - behaves correctly
   //Win32 tested - behaves correctly
+  //Gtk2 tested - behaves correctly
+  //Qt5 tested - behaves correctly
   Result := 0;
   {$ENDIF}
 end;
diff --git a/lcl/interfaces/gtk2/gtk2proc.inc b/lcl/interfaces/gtk2/gtk2proc.inc
index f5d96b1c52..5e2956fe41 100644
--- a/lcl/interfaces/gtk2/gtk2proc.inc
+++ b/lcl/interfaces/gtk2/gtk2proc.inc
@@ -6689,6 +6689,7 @@ begin
       WidthHeightChanged:= true;
     end;
     if WidthHeightChanged then begin
+      SetWindowSizeAndPosition(PGtkWindow(MainWidget), LCLControl);
       SetResizeRequest(MainWidget);
       SetWidgetConstraints(LCLControl);
     end;