diff --git a/lcl/interfaces/qt/qtwidgets.pas b/lcl/interfaces/qt/qtwidgets.pas
index f74ac850b2..211d7057de 100644
--- a/lcl/interfaces/qt/qtwidgets.pas
+++ b/lcl/interfaces/qt/qtwidgets.pas
@@ -6853,7 +6853,10 @@ begin
   QLayout_invalidate(ALayout);
 
   if LCLObject <> nil then
+  begin
     LCLObject.DoAdjustClientRectChange(False);
+    LCLObject.InvalidateClientRectCache(True);
+  end;
 end;
 
 function TQtGroupBox.CreateWidget(const AParams: TCreateParams): QWidgetH;