diff --git a/mozilla/accessible/src/xul/nsXULSelectAccessible.cpp b/mozilla/accessible/src/xul/nsXULSelectAccessible.cpp
index 9eebc7ddff5..b97efcd7e5d 100644
--- a/mozilla/accessible/src/xul/nsXULSelectAccessible.cpp
+++ b/mozilla/accessible/src/xul/nsXULSelectAccessible.cpp
@@ -379,11 +379,13 @@ NS_IMETHODIMP nsXULListboxAccessible::GetAccState(PRUint32 *_retval)
   */
 NS_IMETHODIMP nsXULListboxAccessible::GetAccValue(nsAString& _retval)
 {
+  _retval.Truncate();
   nsCOMPtr<nsIDOMXULSelectControlElement> select(do_QueryInterface(mDOMNode));
   if (select) {
     nsCOMPtr<nsIDOMXULSelectControlItemElement> selectedItem;
     select->GetSelectedItem(getter_AddRefs(selectedItem));
-    return selectedItem->GetValue(_retval);
+    if (selectedItem)
+      return selectedItem->GetValue(_retval);
   }
   return NS_ERROR_FAILURE;
 }
diff --git a/mozilla/xpfe/global/resources/content/bindings/listbox.xml b/mozilla/xpfe/global/resources/content/bindings/listbox.xml
index 00b8d0a9b6d..30061beac24 100644
--- a/mozilla/xpfe/global/resources/content/bindings/listbox.xml
+++ b/mozilla/xpfe/global/resources/content/bindings/listbox.xml
@@ -27,7 +27,7 @@
       </xul:listrows>
     </content>
     
-    <implementation implements="nsIDOMXULMultiSelectControlElement, nsIAccessibleProvider">
+    <implementation implements="nsIDOMXULMultiSelectControlElement, nsIDOMXULSelectControlElement, nsIAccessibleProvider">
       <field name="_isUpSelection">0</field>
       <field name="_isDownSelection">0</field>
       <field name="_suppressOnSelect">false</field>
diff --git a/mozilla/xpfe/global/resources/content/bindings/menulist.xml b/mozilla/xpfe/global/resources/content/bindings/menulist.xml
index 1e1c567d9f6..1696086476b 100644
--- a/mozilla/xpfe/global/resources/content/bindings/menulist.xml
+++ b/mozilla/xpfe/global/resources/content/bindings/menulist.xml
@@ -39,7 +39,7 @@
       </handler>
     </handlers>
 
-    <implementation implements="nsIDOMXULMenuListElement, nsIAccessibleProvider">
+    <implementation implements="nsIDOMXULMenuListElement, nsIDOMXULSelectControlElement, nsIAccessibleProvider">
       <constructor>
         this.setInitialSelection()
       </constructor>