diff --git a/accessible/src/xul/XULTreeGridAccessible.cpp b/accessible/src/xul/XULTreeGridAccessible.cpp
index 6383831a6e4a..b88e1185ccc5 100644
--- a/accessible/src/xul/XULTreeGridAccessible.cpp
+++ b/accessible/src/xul/XULTreeGridAccessible.cpp
@@ -298,7 +298,6 @@ ClearCache(tmp->mAccessibleCache);
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(XULTreeGridRowAccessible)
-NS_INTERFACE_MAP_STATIC_AMBIGUOUS(XULTreeGridRowAccessible)
 NS_INTERFACE_MAP_END_INHERITING(XULTreeItemAccessibleBase)
 
 NS_IMPL_ADDREF_INHERITED(XULTreeGridRowAccessible,