diff --git a/accessible/src/base/nsAccessible.h b/accessible/src/base/nsAccessible.h
index a3a3df0baa3f..034b522c3917 100644
--- a/accessible/src/base/nsAccessible.h
+++ b/accessible/src/base/nsAccessible.h
@@ -251,7 +251,7 @@ public:
   /**
    * Return parent accessible.
    */
-  nsAccessible* GetParent();
+  virtual nsAccessible* GetParent();
 
   /**
    * Return child accessible at the given index.
diff --git a/accessible/src/base/nsApplicationAccessible.cpp b/accessible/src/base/nsApplicationAccessible.cpp
index 9e5738961c07..665cd07e046d 100644
--- a/accessible/src/base/nsApplicationAccessible.cpp
+++ b/accessible/src/base/nsApplicationAccessible.cpp
@@ -410,6 +410,12 @@ nsApplicationAccessible::InvalidateChildren()
   // and RemoveChild() method calls.
 }
 
+nsAccessible*
+nsApplicationAccessible::GetParent()
+{
+  return nsnull;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // nsAccessible protected methods
 
diff --git a/accessible/src/base/nsApplicationAccessible.h b/accessible/src/base/nsApplicationAccessible.h
index ae375260c9a9..7d20fa4c3063 100644
--- a/accessible/src/base/nsApplicationAccessible.h
+++ b/accessible/src/base/nsApplicationAccessible.h
@@ -131,6 +131,8 @@ public:
 
   virtual void InvalidateChildren();
 
+  virtual nsAccessible* GetParent();
+
 protected:
 
   // nsAccessible