diff --git a/lcl/include/wincontrol.inc b/lcl/include/wincontrol.inc
index 0b45dd537c..5b77346989 100644
--- a/lcl/include/wincontrol.inc
+++ b/lcl/include/wincontrol.inc
@@ -6681,7 +6681,7 @@ var
   var
     s: String;
   begin
-    s:='TWinControl.WMSize loop detected: '+DbgSName(Self)+' BoundsRealized='+dbgs(FBoundsRealized)+' NewBoundsRealized='+dbgs(NewBoundsRealized);
+    s:='TWinControl.WMSize loop detected, the widgetset does not like the LCL bounds or sends unneeded wmsize messages: '+DbgSName(Self)+' BoundsRealized='+dbgs(FBoundsRealized)+' NewBoundsRealized='+dbgs(NewBoundsRealized);
     if (OldClientSize.cx<>NewClientSize.cx)
       or (OldClientSize.cy<>NewClientSize.cy)
     then
diff --git a/lcl/interfaces/carbon/carbondef.pp b/lcl/interfaces/carbon/carbondef.pp
index 5159ac9dcf..e66d243620 100644
--- a/lcl/interfaces/carbon/carbondef.pp
+++ b/lcl/interfaces/carbon/carbondef.pp
@@ -461,11 +461,23 @@ end;
 procedure TCarbonWidget.UpdateLCLClientRect;
 var
   R: TRect;
+  ClientR: TRect;
+  LCLR: TRect;
+  LCLClientR: TRect;
+  RChanged: Boolean;
+  ClientChanged: Boolean;
 begin
   if not Resizing then begin
     GetBounds(R);
-    LCLObject.InvalidateClientRectCache(False);
-    LCLSendSizeMsg(LCLObject, R.Right - R.Left, R.Bottom - R.Top, Size_SourceIsInterface);
+    GetClientRect(ClientR);
+    LCLR:=LCLObject.BoundsRect;
+    LCLClientR:=LCLObject.ClientRect;
+    RChanged:=not CompareRect(@R,@LCLR);
+    ClientChanged:=not CompareRect(@ClientR,@LCLClientR);
+    if not ClientChanged then
+      LCLObject.InvalidateClientRectCache(False);
+    if RChanged or ClientChanged then
+      LCLSendSizeMsg(LCLObject, R.Right - R.Left, R.Bottom - R.Top, Size_SourceIsInterface);
   end;
 end;