diff --git a/src/applications/conduit/method/differential/getdiff/ConduitAPI_differential_getdiff_Method.php b/src/applications/conduit/method/differential/getdiff/ConduitAPI_differential_getdiff_Method.php
index 5745d182ce..dab997866d 100644
--- a/src/applications/conduit/method/differential/getdiff/ConduitAPI_differential_getdiff_Method.php
+++ b/src/applications/conduit/method/differential/getdiff/ConduitAPI_differential_getdiff_Method.php
@@ -1,94 +1,94 @@
 <?php
 
 /*
  * Copyright 2011 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 /**
  * @group conduit
  */
 class ConduitAPI_differential_getdiff_Method extends ConduitAPIMethod {
 
   public function getMethodDescription() {
     return "Load the content of a diff from Differential.";
   }
 
   public function defineParamTypes() {
     return array(
       'revision_id' => 'optional id',
       'diff_id'     => 'optional id',
     );
   }
 
   public function defineReturnType() {
     return 'nonempty dict';
   }
 
   public function defineErrorTypes() {
     return array(
       'ERR_BAD_REVISION'    => 'No such revision exists.',
       'ERR_BAD_DIFF'        => 'No such diff exists.',
     );
   }
 
   public function shouldRequireAuthentication() {
     return !PhabricatorEnv::getEnvConfig('differential.anonymous-access');
   }
 
   protected function execute(ConduitAPIRequest $request) {
     $diff = null;
 
     $revision_id = $request->getValue('revision_id');
     if ($revision_id) {
       $revision = id(new DifferentialRevision())->load($revision_id);
       if (!$revision) {
         throw new ConduitException('ERR_BAD_REVISION');
       }
       $diff = id(new DifferentialDiff())->loadOneWhere(
         'revisionID = %d ORDER BY id DESC LIMIT 1',
         $revision->getID());
     } else {
       $diff_id = $request->getValue('diff_id');
       if ($diff_id) {
         $diff = id(new DifferentialDiff())->load($diff_id);
       }
     }
 
     if (!$diff) {
       throw new ConduitException('ERR_BAD_DIFF');
     }
 
     $diff->attachChangesets($diff->loadChangesets());
     // TODO: We could batch this to improve performance.
     foreach ($diff->getChangesets() as $changeset) {
       $changeset->attachHunks($changeset->loadHunks());
     }
 
     $basic_dict = $diff->getDiffDict();
 
     // for conduit calls, the basic dict is not enough
     // we also need to include the arcanist project
     $project = $diff->loadArcanistProject();
     if ($project) {
       $project_name = $project->getName();
     } else {
-      $project_name = '';
+      $project_name = null;
     }
     $basic_dict['projectName'] = $project_name;
 
     return $basic_dict;
   }
 
 }