diff --git a/octoprint_auth_ldap/__init__.py b/octoprint_auth_ldap/__init__.py
index 0333905..0b00da6 100644
--- a/octoprint_auth_ldap/__init__.py
+++ b/octoprint_auth_ldap/__init__.py
@@ -97,7 +97,7 @@ class LDAPUserManager(FilebasedUserManager,
                 else:
                     group_filter = "(cn=%s)" % groups
 
-                group_filter = "cn=octoprint,ou=Groups,ou=People,dc=edinburghhacklab,dc=com"
+                group_filter = "(cn=octoprint,ou=Groups,ou=People,dc=edinburghhacklab,dc=com)"
 
                 query = "(&(objectClass=posixGroup)%s(memberUid=%s))" % (group_filter, userid)
                 self._logger.error("LDAP-AUTH QUERY:" + query)