diff --git a/dynamicweb2/ldap_manager.py b/dynamicweb2/ldap_manager.py
index 498855a..d40e931 100644
--- a/dynamicweb2/ldap_manager.py
+++ b/dynamicweb2/ldap_manager.py
@@ -250,7 +250,7 @@ class LdapManager:
         :return:
         """
         with open(settings.LDAP_MAX_UID_FILE_PATH, 'w+') as handler:
-            handler.write(max_uid)
+            handler.write(str(max_uid))
 
     def _get_max_uid(self):
         """