diff --git a/mozilla/accessible/src/base/nsDocAccessible.cpp b/mozilla/accessible/src/base/nsDocAccessible.cpp
index eee97f10cb4..2c80f9861ea 100644
--- a/mozilla/accessible/src/base/nsDocAccessible.cpp
+++ b/mozilla/accessible/src/base/nsDocAccessible.cpp
@@ -1142,7 +1142,7 @@ nsDocAccessible::ARIAAttributeChanged(nsIContent* aContent, nsIAtom* aAttribute)
     // The activedescendant universal property redirects accessible focus events
     // to the element with the id that activedescendant points to
     nsCOMPtr<nsIDOMNode> currentFocus = GetCurrentFocus();
-    if (currentFocus == targetNode) {
+    if (SameCOMIdentity(GetRoleContent(currentFocus), targetNode)) {
       nsRefPtr<nsRootAccessible> rootAcc = GetRootAccessible();
       if (rootAcc)
         rootAcc->FireAccessibleFocusEvent(nsnull, currentFocus, nsnull, PR_TRUE);
diff --git a/mozilla/accessible/src/base/nsRootAccessible.cpp b/mozilla/accessible/src/base/nsRootAccessible.cpp
index 97d8d6df920..ccde5254599 100644
--- a/mozilla/accessible/src/base/nsRootAccessible.cpp
+++ b/mozilla/accessible/src/base/nsRootAccessible.cpp
@@ -463,7 +463,9 @@ PRBool nsRootAccessible::FireAccessibleFocusEvent(nsIAccessible *aAccessible,
       domDoc->GetElementById(id, getter_AddRefs(relatedEl));
       finalFocusNode = do_QueryInterface(relatedEl);
       if (!finalFocusNode) {
-        return PR_FALSE;
+        // If aria-activedescendant is set to nonextistant ID, then treat as focus
+        // on the activedescendant container (which has real DOM focus)
+        finalFocusNode = aNode;
       }
       finalFocusAccessible = nsnull;
     }