diff --git a/lcl/include/wincontrol.inc b/lcl/include/wincontrol.inc
index b6a5cbcdaf..5f29ce7f7c 100644
--- a/lcl/include/wincontrol.inc
+++ b/lcl/include/wincontrol.inc
@@ -6566,6 +6566,7 @@ begin
         RaiseGDBException('Handle creation failed creating '+DbgSName(Self));
       //debugln('TWinControl.CreateWnd ',DbgSName(Self));
       Constraints.UpdateInterfaceConstraints;
+      InvalidateClientRectCache(False);
       InvalidatePreferredSize;
       TWSWinControlClass(WidgetSetClass).ConstraintsChange(Self);