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 2968079017..df9a28d00b 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
@@ -43,6 +43,10 @@ class ConduitAPI_differential_getdiff_Method extends ConduitAPIMethod {
     );
   }
 
+  public function shouldRequireAuthentication() {
+    return !PhabricatorEnv::getEnvConfig('differential.anonymous-access');
+  }
+
   protected function execute(ConduitAPIRequest $request) {
     $diff = null;
 
diff --git a/src/applications/conduit/method/differential/getdiff/__init__.php b/src/applications/conduit/method/differential/getdiff/__init__.php
index 15399190d3..ee5f6cc825 100644
--- a/src/applications/conduit/method/differential/getdiff/__init__.php
+++ b/src/applications/conduit/method/differential/getdiff/__init__.php
@@ -10,6 +10,7 @@ phutil_require_module('phabricator', 'applications/conduit/method/base');
 phutil_require_module('phabricator', 'applications/conduit/protocol/exception');
 phutil_require_module('phabricator', 'applications/differential/storage/diff');
 phutil_require_module('phabricator', 'applications/differential/storage/revision');
+phutil_require_module('phabricator', 'infrastructure/env');
 
 phutil_require_module('phutil', 'utils');