diff --git a/src/core/nswindow_proxy.h b/src/core/nswindow_proxy.h
index e8c742d..fa25ba6 100644
--- a/src/core/nswindow_proxy.h
+++ b/src/core/nswindow_proxy.h
@@ -18,13 +18,14 @@ class NSWindowProxy
 {
 private:
     NSWindow* m_window;
+    QWindow* m_qtwindow;
     scoped_nsobject<WindowButtonsProxy> m_buttonProxy;
     scoped_nsobject<NSWindowProxyDelegate> m_windowDelegate;
     bool m_windowButtonVisibility;
     QPoint m_trafficLightPosition;
 
 public:
-    NSWindowProxy(NSWindow *window);
+    NSWindowProxy(NSWindow *window, QWindow *qtwindow);
     ~NSWindowProxy();
 
     NSWindow* window() { return m_window; }
@@ -44,6 +45,7 @@ public:
     void notifyWindowLeaveFullScreen();
     void notifyWindowWillEnterFullScreen();
     void notifyWindowWillLeaveFullScreen();
+    void notifyWindowCloseButtonClicked();
 
 };
 
diff --git a/src/core/nswindow_proxy.mm b/src/core/nswindow_proxy.mm
index 398a68a..6a0dee5 100644
--- a/src/core/nswindow_proxy.mm
+++ b/src/core/nswindow_proxy.mm
@@ -1,6 +1,7 @@
 #include "nswindow_proxy.h"
 
 #include <QtGui/qguiapplication.h>
+#include <QtGui/qwindow.h>
 
 static QList<NSWindow*> gFlsWindows;
 static bool gNSWindowOverrode = false;
@@ -160,10 +161,11 @@ static void restoreNSWindowMethods(NSWindow* window)
 
 }
 
-NSWindowProxy::NSWindowProxy(NSWindow *window)
+NSWindowProxy::NSWindowProxy(NSWindow *window, QWindow *qtwindow)
     : m_windowButtonVisibility(false)
     , m_buttonProxy(nullptr)
     , m_window(window)
+    , m_qtwindow(qtwindow)
 {
     overrideNSWindowMethods(window);
     m_buttonProxy.reset([[WindowButtonsProxy alloc] initWithWindow:window]);
@@ -240,6 +242,11 @@ void NSWindowProxy::notifyWindowWillLeaveFullScreen() {
     }
 }
 
+void NSWindowProxy::notifyWindowCloseButtonClicked() {
+    // Call QWindow::close() when button clicked.
+    m_qtwindow->close();
+}
+
 @implementation NSWindowProxyDelegate
 - (id)initWithWindowProxy:(NSWindowProxy*)proxy {
     m_windowProxy = proxy;
@@ -288,4 +295,10 @@ void NSWindowProxy::notifyWindowWillLeaveFullScreen() {
 - (void)windowDidExitFullScreen:(NSNotification*)notification {
     m_windowProxy->notifyWindowLeaveFullScreen();
 }
+
+- (BOOL)windowShouldClose:(id)window {
+    // We will override default close behavior
+    m_windowProxy->notifyWindowCloseButtonClicked();
+    return NO;
+}
 @end
diff --git a/src/core/utilities_macos.mm b/src/core/utilities_macos.mm
index c11b1af..dde3b65 100644
--- a/src/core/utilities_macos.mm
+++ b/src/core/utilities_macos.mm
@@ -143,7 +143,7 @@ bool setMacWindowHook(QWindow* w)
     if (nswindow == nullptr)
         return false;
 
-    NSWindowProxy *obj = new NSWindowProxy(nswindow);
+    NSWindowProxy *obj = new NSWindowProxy(nswindow, w);
     gQWindowToNSWindow.insert(w, obj);
 
     return true;