diff --git a/toolkit/components/autocomplete/src/nsAutoCompleteController.cpp b/toolkit/components/autocomplete/src/nsAutoCompleteController.cpp
index c0b94d2407a..098c1f3857b 100644
--- a/toolkit/components/autocomplete/src/nsAutoCompleteController.cpp
+++ b/toolkit/components/autocomplete/src/nsAutoCompleteController.cpp
@@ -331,9 +331,13 @@ nsAutoCompleteController::HandleStartComposition()
 
   PRBool isOpen = PR_FALSE;
   input->GetPopupOpen(&isOpen);
-  if (isOpen)
+  if (isOpen) {
     ClosePopup();
-  mPopupClosedByCompositionStart = isOpen;
+
+    PRBool stillOpen = PR_FALSE;
+    input->GetPopupOpen(&stillOpen);
+    mPopupClosedByCompositionStart = !stillOpen;
+  }
   return NS_OK;
 }