diff --git a/ceilometer/storage/impl_mongodb.py b/ceilometer/storage/impl_mongodb.py
index 7216d82d..488cf6bb 100644
--- a/ceilometer/storage/impl_mongodb.py
+++ b/ceilometer/storage/impl_mongodb.py
@@ -253,24 +253,20 @@ class Connection(base.Connection):
 
         :param source: Optional source filter.
         """
+        q = {}
         if source is not None:
-            q = {'source': source,
-                 }
-            return self.db.user.find(q).distinct('_id')
-        else:
-            return self.db.user.distinct('_id')
+            q['source'] = source
+        return sorted(self.db.user.find(q).distinct('_id'))
 
     def get_projects(self, source=None):
         """Return an iterable of project id strings.
 
         :param source: Optional source filter.
         """
+        q = {}
         if source is not None:
-            q = {'source': source,
-                 }
-            return self.db.project.find(q).distinct('_id')
-        else:
-            return self.db.project.distinct('_id')
+            q['source'] = source
+        return sorted(self.db.project.find(q).distinct('_id'))
 
     def get_resources(self, user=None, project=None, source=None):
         """Return an iterable of dictionaries containing resource information.