diff --git a/pylons_app/lib/hooks.py b/pylons_app/lib/hooks.py
--- a/pylons_app/lib/hooks.py
+++ b/pylons_app/lib/hooks.py
@@ -63,10 +63,10 @@ def user_action_mapper(ui, repo, hooktyp
         username = kwargs['url'].split(':')[-1]
         user_log = sa.query(UserLog)\
             .filter(UserLog.user == sa.query(User)\
-                                        .filter(User.username == username).one())\
+                                    .filter(User.username == username).one())\
             .order_by(UserLog.user_log_id.desc()).first()
-            
-        if not user_log.revision:
+        
+        if user_log and not user_log.revision:
             user_log.revision = str(repo['tip'])
             sa.add(user_log)
             sa.commit()