diff --git a/endpoints/index.py b/endpoints/index.py
index 3cad81b48..00020d317 100644
--- a/endpoints/index.py
+++ b/endpoints/index.py
@@ -78,10 +78,12 @@ def create_user():
 @app.route('/v1/users/', methods=['GET'])
 @process_auth
 def get_user():
-  return jsonify({
-    'username': get_authenticated_user().username,
-    'email': get_authenticated_user().email,
-  })
+  if get_authenticated_user():  
+    return jsonify({
+      'username': get_authenticated_user().username,
+      'email': get_authenticated_user().email,
+    })
+  abort(404)
 
 
 @app.route('/v1/users/<username>/', methods=['PUT'])
@@ -219,18 +221,18 @@ def get_repository_images(namespace, repository):
 @parse_repository_name
 @generate_headers(role='write')
 def delete_repository_images(namespace, repository):
-  pass
+  return make_response('Not Implemented', 501)
 
 
 @app.route('/v1/repositories/<path:repository>/auth', methods=['PUT'])
 @parse_repository_name
 def put_repository_auth(namespace, repository):
-  pass
+  return make_response('Not Implemented', 501)
 
 
 @app.route('/v1/search', methods=['GET'])
 def get_search():
-  pass
+  return make_response('Not Implemented', 501)
 
 
 @app.route('/_ping')