diff --git a/data/model/repository.py b/data/model/repository.py
index 948d97cac..13499904f 100644
--- a/data/model/repository.py
+++ b/data/model/repository.py
@@ -231,6 +231,8 @@ def get_visible_repositories(username, namespace=None, include_public=False):
   """ Returns the repositories visible to the given user (if any).
   """
   if not include_public and not username:
+    # Short circuit by returning a query that will find no repositories. We need to return a query
+    # here, as it will be modified by other queries later on.
     return Repository.select().where(Repository.id == -1)
 
   query = (Repository
@@ -394,6 +396,6 @@ def list_popular_public_repos(action_count_threshold, time_span):
           .join(RepositoryActionCount)
           .where(RepositoryActionCount.date >= cutoff,
                  Repository.visibility == get_public_repo_visibility())
-          .group_by(RepositoryActionCount.repository)
+          .group_by(RepositoryActionCount.repository, Repository.name, Namespace.username)
           .having(fn.Sum(RepositoryActionCount.count) >= action_count_threshold)
           .tuples())