diff --git a/examples/OpenGLWindow/MacOpenGLWindowObjC.m b/examples/OpenGLWindow/MacOpenGLWindowObjC.m
index 31fab0df0..6294f354c 100644
--- a/examples/OpenGLWindow/MacOpenGLWindowObjC.m
+++ b/examples/OpenGLWindow/MacOpenGLWindowObjC.m
@@ -1,8 +1,11 @@
 #ifndef B3_USE_GLFW
+#define __OBJC2__ 1
+#include <Foundation/NSExtensionContext.h>
 
 #include "MacOpenGLWindowObjC.h"
 
 #define GL_DO_NOT_WARN_IF_MULTI_GL_VERSION_HEADERS_INCLUDED
+
 #import <Cocoa/Cocoa.h>
 #include "OpenGLInclude.h"