diff --git a/lcl/interfaces/cocoa/cocoaint.pas b/lcl/interfaces/cocoa/cocoaint.pas
index 90c180816d..96e120421e 100644
--- a/lcl/interfaces/cocoa/cocoaint.pas
+++ b/lcl/interfaces/cocoa/cocoaint.pas
@@ -54,7 +54,7 @@ type
 
   { TCocoaAppDelegate }
 
-  TCocoaAppDelegate = objcclass(NSObject)
+  TCocoaAppDelegate = objcclass(NSObject, NSApplicationDelegateProtocol)
     function applicationShouldTerminate(sender: NSApplication): NSApplicationTerminateReply; message 'applicationShouldTerminate:';
   end;
 
diff --git a/lcl/interfaces/cocoa/cocoaprivate.pp b/lcl/interfaces/cocoa/cocoaprivate.pp
index 1c5a910b4c..432a93610f 100644
--- a/lcl/interfaces/cocoa/cocoaprivate.pp
+++ b/lcl/interfaces/cocoa/cocoaprivate.pp
@@ -159,7 +159,7 @@ type
 
   { TCocoaWindow }
 
-  TCocoaWindow = objcclass(NSWindow)
+  TCocoaWindow = objcclass(NSWindow, NSWindowDelegateProtocol)
   protected
     function windowShouldClose(sender : id): LongBool; message 'windowShouldClose:';
     procedure windowWillClose(notification: NSNotification); message 'windowWillClose:';
@@ -208,7 +208,7 @@ type
 
   { TCocoaComboBox }
 
-  TCocoaComboBox = objcclass(NSComboBox)
+  TCocoaComboBox = objcclass(NSComboBox, NSComboBoxDataSourceProtocol)
     callback  : TCommonCallback;
     list      : TCocoaComboBoxList;
     function comboBox_objectValueForItemAtIndex_(combo: TCocoaComboBox; row: NSInteger): id;
@@ -238,7 +238,7 @@ type
 
   { TCocoaListView }
 
-  TCocoaListView = objcclass(NSTableView)
+  TCocoaListView = objcclass(NSTableView, NSTableViewDataSourceProtocol)
     callback  : TCommonCallback;
     list      : TCocoaStringList;
     function numberOfRowsInTableView(aTableView: NSTableView): NSInteger; message 'numberOfRowsInTableView:';