diff --git a/accessible/src/base/nsAccessibilityService.cpp b/accessible/src/base/nsAccessibilityService.cpp
index 2a14a46d00a..7906521ccdd 100644
--- a/accessible/src/base/nsAccessibilityService.cpp
+++ b/accessible/src/base/nsAccessibilityService.cpp
@@ -289,10 +289,7 @@ nsAccessibilityService::GetInfo(nsISupports* aFrame, nsIFrame** aRealFrame, nsIW
   if (!document)
     return NS_ERROR_FAILURE;
 
-#ifdef DEBUG_A11Y
-  PRInt32 shells = document->GetNumberOfShells();
-  NS_ASSERTION(shells > 0,"Error no shells!");
-#endif
+  NS_ASSERTION(document->GetPrimaryShell(),"Error no shells!");
 
   // do_GetWR only works into a |nsCOMPtr| :-(
   nsCOMPtr<nsIWeakReference> weakShell =
diff --git a/extensions/access-builtin/accessproxy/nsAccessProxy.cpp b/extensions/access-builtin/accessproxy/nsAccessProxy.cpp
index 714f051fa7f..f11718c34a8 100644
--- a/extensions/access-builtin/accessproxy/nsAccessProxy.cpp
+++ b/extensions/access-builtin/accessproxy/nsAccessProxy.cpp
@@ -140,7 +140,7 @@ NS_IMETHODIMP nsAccessProxy::HandleEvent(nsIDOMEvent* aEvent)
   domNode->GetOwnerDocument(getter_AddRefs(domDoc));
   if (domDoc) {
     doc = do_QueryInterface(domDoc);
-    if (doc && doc->GetNumberOfShells()>0) {
+    if (doc) {
       presShell = doc->GetPrimaryShell();
     }
   }