diff --git a/flaschengeist/plugins/auth_ldap/__init__.py b/flaschengeist/plugins/auth_ldap/__init__.py
index 7bcefc7..c3ae7c6 100644
--- a/flaschengeist/plugins/auth_ldap/__init__.py
+++ b/flaschengeist/plugins/auth_ldap/__init__.py
@@ -54,7 +54,7 @@ class AuthLDAP(AuthPlugin):
 
     def find_user(self, userid, mail=None):
         attr = self.__find(userid, mail)
-        if attr:
+        if attr is not None:
             user = User(userid=attr["uid"][0])
             self.__update(user, attr)
             return user
@@ -186,7 +186,7 @@ class AuthLDAP(AuthPlugin):
             SUBTREE,
             attributes=["uid", "givenName", "sn", "mail"],
         )
-        return con.response[0]["attributes"]
+        return con.response[0]["attributes"] if len(con.response) > 0 else None
 
     def __update(self, user, attr):
         """Update an User object with LDAP attributes"""