--- a/widget/cocoa/nsChildView.mm
+++ b/widget/cocoa/nsChildView.mm
@@ -2671,18 +2671,18 @@ NSEvent* gLastDragMouseDownEvent = nil; 
   NS_ENSURE_TRUE(rollupListener, false);
   nsCOMPtr<nsIWidget> rollupWidget = rollupListener->GetRollupWidget();
   if (rollupWidget) {
     NSWindow* currentPopup = static_cast<NSWindow*>(rollupWidget->GetNativeData(NS_NATIVE_WINDOW));
     if (!nsCocoaUtils::IsEventOverWindow(theEvent, currentPopup)) {
       // event is not over the rollup window, default is to roll up
       bool shouldRollup = true;
 
-      // check to see if scroll events should roll up the popup
-      if ([theEvent type] == NSScrollWheel) {
+      // check to see if scroll/zoom events should roll up the popup
+      if ([theEvent type] == NSScrollWheel || [theEvent type] == NSEventTypeMagnify) {
         shouldRollup = rollupListener->ShouldRollupOnMouseWheelEvent();
         // consume scroll events that aren't over the popup
         // unless the popup is an arrow panel
         consumeEvent = rollupListener->ShouldConsumeOnMouseWheelEvent();
       }
 
       // if we're dealing with menus, we probably have submenus and
       // we don't want to rollup if the click is in a parent menu of