diff --git a/lib/util.php b/lib/util.php
index a061d17739..4a87f9a217 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -1040,7 +1040,9 @@ function common_linkify($url) {
  */
 function common_shorten_links($text, $always = false, User $user=null)
 {
-    $user = common_current_user();
+    if ($user === null) {
+        $user = common_current_user();
+    }
 
     $maxLength = User_urlshortener_prefs::maxNoticeLength($user);