diff --git a/layout/xul/base/src/nsXULPopupManager.cpp b/layout/xul/base/src/nsXULPopupManager.cpp
index d198691b0050..bf1bfcf7dcb3 100644
--- a/layout/xul/base/src/nsXULPopupManager.cpp
+++ b/layout/xul/base/src/nsXULPopupManager.cpp
@@ -603,7 +603,7 @@ nsXULPopupManager::HidePopupCallback(nsIContent* aPopup,
                                      nsPopupType aPopupType,
                                      PRBool aDeselectMenu)
 {
-  if (mCloseTimer) {
+  if (mCloseTimer && mTimerMenu == aPopupFrame) {
     mCloseTimer->Cancel();
     mCloseTimer = nsnull;
     mTimerMenu = nsnull;