diff --git a/endpoints/api/repository.py b/endpoints/api/repository.py
index 6950402fe..2c59851d6 100644
--- a/endpoints/api/repository.py
+++ b/endpoints/api/repository.py
@@ -159,7 +159,14 @@ class RepositoryList(ApiResource):
 
       repo_query = model.repository.get_user_starred_repositories(user)
     else:
-      repo_query = model.repository.get_visible_repositories(username=username,
+      # TEMP: Only supply the filter username if a specific namespace is requested. If the request
+      # is for all public repositories, simply return them. This ensures that we don't paginate
+      # over a union query.
+      # TODO(jschorr): Fix pagination for union queries so we can remove this restriction!
+      filter_username = (username if not parsed_args['namespace'] and not parsed_args['starred']
+                         else None)
+
+      repo_query = model.repository.get_visible_repositories(username=filter_username,
                                                              include_public=parsed_args['public'],
                                                              namespace=parsed_args['namespace'])