diff --git a/html/includes/authentication/ldap.inc.php b/html/includes/authentication/ldap.inc.php
index daf7941d0..11e3a20b5 100644
--- a/html/includes/authentication/ldap.inc.php
+++ b/html/includes/authentication/ldap.inc.php
@@ -7,6 +7,10 @@ function authenticate($username,$password)
   $ds=@ldap_connect($config['auth_ldap_server'],$config['auth_ldap_port']);
   if ($ds)
   {
+    if ($config['auth_ldap_version'])
+    {
+      ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, $config['auth_ldap_version']);
+    }
     if (ldap_bind($ds, $config['auth_ldap_prefix'] . $username . $config['auth_ldap_suffix'], $password))
     {
       if (!$config['auth_ldap_group'])
diff --git a/includes/defaults.inc.php b/includes/defaults.inc.php
index 55a669439..96e96f709 100644
--- a/includes/defaults.inc.php
+++ b/includes/defaults.inc.php
@@ -106,5 +106,8 @@ $config['ignore_bsd_os_drives']   = array("/^\/dev,/", "/^\/var\/dhcpd\/dev,/",
 $config['enable_ports_etherlike']       = 0; # Enable EtherLike-MIB
 $config['enable_ports_junoseatmvc']     = 0; # Enable JunOSe ATM VC Discovery/Poller
 
+# LDAP Authentication
+
+$config['auth_ldap_version'] = 3; # v2 or v3
 
 ?>