diff --git a/rhodecode/controllers/summary.py b/rhodecode/controllers/summary.py
--- a/rhodecode/controllers/summary.py
+++ b/rhodecode/controllers/summary.py
@@ -192,7 +192,7 @@ class SummaryController(BaseRepoControll
     @jsonify
     def repo_size(self, repo_name):
         if request.is_xhr:
-            return _('repository size: %s') % c.rhodecode_db_repo._repo_size()
+            return c.rhodecode_db_repo._repo_size()
         else:
             raise HTTPBadRequest()