diff --git a/CRM/Contact/BAO/Contact/Utils.php b/CRM/Contact/BAO/Contact/Utils.php
index 81a93b376c9fd753645f0214df1d99d8f774b351..7c36b4c5ae1b3c9c78384cab7a83f98a7f999df1 100644
--- a/CRM/Contact/BAO/Contact/Utils.php
+++ b/CRM/Contact/BAO/Contact/Utils.php
@@ -228,8 +228,9 @@ WHERE  id IN ( $idString )
     $inputLF = CRM_Utils_Array::value(2, $input);
 
     $check = self::generateChecksum($contactID, $inputTS, $inputLF);
-
-    if (!hash_equals($check, $inputCheck)) {
+    // Joomla_11 - If $inputcheck is null without explicitly casting to a string
+    // you get an error.
+    if (!hash_equals($check, (string) $inputCheck)) {
       return FALSE;
     }