diff --git a/VERSION b/VERSION
index 70ac2e31..130d5fbb 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-Version 1.99.4 (2012-02-25 15:49:09) stable
+Version 1.99.4 (2012-02-26 15:34:08) stable
diff --git a/gluon/tools.py b/gluon/tools.py
index d8394054..5c5cc9cd 100644
--- a/gluon/tools.py
+++ b/gluon/tools.py
@@ -2451,7 +2451,8 @@ class Auth(object):
         return form
 
     def is_impersonating(self):
-        return current.session.auth.impersonator
+        if not current.session.auth: return None
+        return current.session.auth.get('impersonator',None)
 
     def impersonate(self, user_id=DEFAULT):
         """