diff --git a/lcl/interfaces/qt/qtwidgets.pas b/lcl/interfaces/qt/qtwidgets.pas
index 2a6fab80c7..7fec8793fd 100644
--- a/lcl/interfaces/qt/qtwidgets.pas
+++ b/lcl/interfaces/qt/qtwidgets.pas
@@ -8431,7 +8431,13 @@ begin
     if Result then
       QEvent_ignore(Event)
     else
-      Result:=inherited EventFilter(Sender, Event);
+    begin
+      // issue #26040
+      if (QEvent_type(Event) = QEventResize) then
+        LCLObject.DoAdjustClientRectChange
+      else
+        Result:=inherited EventFilter(Sender, Event);
+    end;
   end else
     Result:=inherited EventFilter(Sender, Event);
 end;