diff --git a/scripts/gitadmin/rebuild_gitadmin.php b/scripts/gitadmin/rebuild_gitadmin.php
index dca9e7e686..c9b8776b84 100755
--- a/scripts/gitadmin/rebuild_gitadmin.php
+++ b/scripts/gitadmin/rebuild_gitadmin.php
@@ -44,7 +44,7 @@ function handleSingleUserPHID(
   foreach ($keys as $key) {
     $escaped_key_name = escape_name($key->getName());
     $member = 'PHAB_'.$user->getUserName().
-      '@'.$escaped_key_name.
+      '_'.$escaped_key_name.
       '_'.$key->getID();
     $members[] = $member;
     if (!array_key_exists($member, $used_keys)) {