diff --git a/inc/drivers_ldap.php b/inc/drivers_ldap.php
index f087ac51..68d1f9e7 100644
--- a/inc/drivers_ldap.php
+++ b/inc/drivers_ldap.php
@@ -474,6 +474,11 @@ function fix_unique_member($list) {
 */
 function sync_LDAP_groups(){
   global $c;
+
+  // Can only sync if we know where to find the groups.
+  if (! isset($c->authenticate_hook['config']['baseDNGroups']) )
+      return;
+
   $ldapDriver = getStaticLdap();
   if ( ! $ldapDriver->valid ) return;