diff --git a/run_flaschengeist b/run_flaschengeist
index 661f173..6ba88c2 100644
--- a/run_flaschengeist
+++ b/run_flaschengeist
@@ -180,7 +180,7 @@ def ldap(arguments):
             from ldap3 import SUBTREE
 
             auth_ldap: AuthLDAP = app.config.get("FG_AUTH_BACKEND")
-            if auth_ldap is None and isinstance(auth_ldap, AuthLDAP):
+            if auth_ldap is None or not isinstance(auth_ldap, AuthLDAP):
                 raise Exception("Plugin >auth_ldap< not found")
             conn = auth_ldap.ldap.connection
             if not conn: