diff --git a/lib/SimpleSAML/Auth/LDAP.php b/lib/SimpleSAML/Auth/LDAP.php
index 1bd7299f2fa0620121f98d5bbf1ca25afb52b3e0..d1ca13da9c07fada4530dcdc63d4ae225cabbef7 100644
--- a/lib/SimpleSAML/Auth/LDAP.php
+++ b/lib/SimpleSAML/Auth/LDAP.php
@@ -239,7 +239,7 @@ class LDAP
         $filter = '(|'.$filter.')';
 
         // Append LDAP filters if defined
-        if ($searchFilter != null) {
+        if ($searchFilter !== null) {
             $filter = "(&".$filter."".$searchFilter.")";
         }