diff --git a/widget/src/cocoa/nsCocoaWindow.mm b/widget/src/cocoa/nsCocoaWindow.mm
index 8c34da67e25..640ff84d5bb 100644
--- a/widget/src/cocoa/nsCocoaWindow.mm
+++ b/widget/src/cocoa/nsCocoaWindow.mm
@@ -1833,6 +1833,14 @@ bool nsCocoaWindow::ShouldFocusPlugin()
   mGeckoWindow->ReportSizeEvent();
 }
 
+- (void)windowDidChangeScreen:(NSNotification *)aNotification
+{
+  if (!mGeckoWindow)
+    return;
+
+  mGeckoWindow->ReportMoveEvent();
+}
+
 - (void)windowDidBecomeMain:(NSNotification *)aNotification
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;