diff --git a/lcl/interfaces/cocoa/cocoaprivate.pp b/lcl/interfaces/cocoa/cocoaprivate.pp
index 61c53ea09b..ad886fc58a 100644
--- a/lcl/interfaces/cocoa/cocoaprivate.pp
+++ b/lcl/interfaces/cocoa/cocoaprivate.pp
@@ -31,7 +31,9 @@ uses
   Types, Classes, SysUtils,
   CGGeometry,
   // Libs
-  MacOSAll, CocoaAll, CocoaUtils;
+  MacOSAll, CocoaAll, CocoaUtils,
+  // LCL
+  LCLType;
 
 type
   { LCLObjectExtension }
@@ -40,6 +42,7 @@ type
     function lclIsEnabled: Boolean; message 'lclIsEnabled';
     procedure lclSetEnabled(AEnabled: Boolean); message 'lclSetEnabled:';
     function lclIsVisible: Boolean; message 'lclIsVisible';
+    function lclWindowState: Integer; message 'lclWindowState';
 
     procedure lclInvalidateRect(const r: TRect); message 'lclInvalidateRect:';
     procedure lclInvalidate; message 'lclInvalidate';
@@ -75,6 +78,7 @@ type
 
   LCLWindowExtension = objccategory(NSWindow)
     function lclIsVisible: Boolean; message 'lclIsVisible'; reintroduce;
+    function lclWindowState: Integer; message 'lclWindowState'; reintroduce;
     procedure lclInvalidateRect(const r: TRect); message 'lclInvalidateRect:'; reintroduce;
     procedure lclInvalidate; message 'lclInvalidate'; reintroduce;
     procedure lclLocalToScreen(var X,Y: Integer); message 'lclLocalToScreen::'; reintroduce;
@@ -113,6 +117,7 @@ type
     procedure CloseQuery(var CanClose: Boolean);
     procedure Close;
     procedure Resize;
+    procedure Move;
   end;
 
   { TCocoaMenu }
@@ -183,6 +188,7 @@ type
     procedure windowDidBecomeKey(notification: NSNotification); message 'windowDidBecomeKey:';
     procedure windowDidResignKey(notification: NSNotification); message 'windowDidResignKey:';
     procedure windowDidResize(notification: NSNotification); message 'windowDidResize:';
+    procedure windowDidMove(notification: NSNotification); message 'windowDidMove:';
   public
     callback: IWindowCallback;
     function acceptsFirstResponder: Boolean; override;
@@ -456,6 +462,11 @@ begin
   callback.Resize;
 end;
 
+procedure TCocoaWindow.windowDidMove(notification: NSNotification);
+begin
+  callback.Move;
+end;
+
 function TCocoaWindow.acceptsFirstResponder: Boolean;
 begin
   Result:=true;
@@ -554,6 +565,11 @@ begin
   Result:=False;
 end;
 
+function LCLObjectExtension.lclWindowState: Integer;
+begin
+  Result := SIZENORMAL;
+end;
+
 procedure LCLObjectExtension.lclInvalidateRect(const r:TRect);
 begin
 
@@ -687,6 +703,17 @@ begin
   Result:=isVisible;
 end;
 
+function LCLWindowExtension.lclWindowState: Integer;
+begin
+  if isMiniaturized then
+    Result := SIZEICONIC
+  else
+  if isZoomed then
+    Result := SIZEFULLSCREEN
+  else
+    Result := SIZENORMAL;
+end;
+
 procedure LCLWindowExtension.lclInvalidateRect(const r: TRect);
 begin
   contentView.lclInvalidateRect(r);
diff --git a/lcl/interfaces/cocoa/cocoawscommon.pas b/lcl/interfaces/cocoa/cocoawscommon.pas
index 75e5eb2856..76df72395c 100644
--- a/lcl/interfaces/cocoa/cocoawscommon.pas
+++ b/lcl/interfaces/cocoa/cocoawscommon.pas
@@ -155,7 +155,8 @@ procedure TLCLCommonCallback.boundsDidChange;
 var
   NewBounds, OldBounds: TRect;
   PosMsg: TLMWindowPosChanged;
-  Resized, Moved: Boolean;
+  Resized, Moved, ClientResized: Boolean;
+  SizeType: Integer;
 begin
   NewBounds := Owner.lclFrame;
   OldBounds := Target.BoundsRect;
@@ -167,6 +168,8 @@ begin
     (OldBounds.Left <> NewBounds.Left) or
     (OldBounds.Top <> NewBounds.Top);
 
+  ClientResized := False;
+
   // send window pos changed
   if Resized or Moved then
   begin
@@ -193,13 +196,14 @@ begin
   if Resized or Target.ClientRectNeedsInterfaceUpdate then
   begin
     Target.InvalidateClientRectCache(False);
+    ClientResized := True;
   end;
 
   // then send a LM_SIZE message
-  if Resized then
+  if Resized or ClientResized then
   begin
     LCLSendSizeMsg(Target, NewBounds.Right - NewBounds.Left,
-      NewBounds.Bottom - NewBounds.Top, Size_SourceIsInterface);
+      NewBounds.Bottom - NewBounds.Top, Owner.lclWindowState, True);
   end;
 
   // then send a LM_MOVE message
diff --git a/lcl/interfaces/cocoa/cocoawsforms.pp b/lcl/interfaces/cocoa/cocoawsforms.pp
index 9c909207d0..138897910b 100644
--- a/lcl/interfaces/cocoa/cocoawsforms.pp
+++ b/lcl/interfaces/cocoa/cocoawsforms.pp
@@ -40,13 +40,14 @@ uses
 type
   { TLCLWindowCallback }
 
-  TLCLWindowCallback=class(TLCLCommonCallBack, IWindowCallback)
+  TLCLWindowCallback = class(TLCLCommonCallBack, IWindowCallback)
   public
     procedure Activate; virtual;
     procedure Deactivate; virtual;
     procedure CloseQuery(var CanClose: Boolean); virtual;
     procedure Close; virtual;
     procedure Resize; virtual;
+    procedure Move; virtual;
   end;
 
 
@@ -168,14 +169,13 @@ begin
 end;
 
 procedure TLCLWindowCallback.Resize;
-var
-  sz  : NSSize;
-  r   : TRect;
 begin
-  sz := NSWindow(Owner).frame.size;
-  TCocoaWSCustomForm.GetClientBounds(TWinControl(Target), r);
-  if Assigned(Target) then
-    LCLSendSizeMsg(Target, Round(sz.width), Round(sz.height), SIZENORMAL);
+  boundsDidChange;
+end;
+
+procedure TLCLWindowCallback.Move;
+begin
+  boundsDidChange;
 end;