diff --git a/inc/PassHash.class.php b/inc/PassHash.class.php
index f857667232b3763d76595a45324d56e578acec11..13be479cc31641e00b9e8dfde2406135f29c8d0d 100644
--- a/inc/PassHash.class.php
+++ b/inc/PassHash.class.php
@@ -132,7 +132,7 @@ class PassHash {
     public function hash_smd5($clear, $salt = null) {
         $this->init_salt($salt, 8);
 
-        if(defined('CRYPT_MD5') && CRYPT_MD5) {
+        if(defined('CRYPT_MD5') && CRYPT_MD5 && $salt !== '') {
             return crypt($clear, '$1$'.$salt.'$');
         } else {
             // Fall back to PHP-only implementation