diff --git a/include/class_ldap.inc b/include/class_ldap.inc
index 2a55657e1841a65d30a5d6b7e3e5f145bdc9e08d..ad80c8c91e4c0a91cd830ad07bf6818d6c4b6642 100644
--- a/include/class_ldap.inc
+++ b/include/class_ldap.inc
@@ -985,7 +985,7 @@ class LDAP
     $admin  = escapeshellarg($this->binddn);
     $filter = escapeshellarg($filter);
 
-    $cmd = "ldapsearch -x -LLLL -D {$admin} {$filter} {$limit} {$scope} -H {$host} -b {$dn} -w {$pwd} ";
+    $cmd = 'ldapsearch'.($this->tls ? ' -ZZ' : '')." -x -LLLL -D {$admin} {$filter} {$limit} {$scope} -H {$host} -b {$dn} -w {$pwd} ";
 
     // Create list of process pipes
     $descriptorspec = array(