--- a/pylib/mozautomation/mozautomation/changetracker.py
+++ b/pylib/mozautomation/mozautomation/changetracker.py
@@ -120,16 +120,18 @@ class ChangeTracker(object):
         tree_id = self.tree_id(tree, url)
 
         last_push_id = self.last_push_id(tree)
         if last_push_id is None:
             last_push_id = -1
 
         with self._db:
             for push_id, push in repo.push_info(start_id=last_push_id + 1):
+                if not push['changesets']:
+                    continue
                 self._db.execute('INSERT INTO pushes (push_id, tree_id, time, '
                 'user) VALUES (?, ?, ?, ?)', [push_id, tree_id, push['date'],
                     push['user']])
 
                 head = buffer(binascii.unhexlify(push['changesets'][-1]))
 
                 params = [(buffer(binascii.unhexlify(c)), head, push_id,
                     tree_id) for c in push['changesets']]