diff --git a/mo/users.py b/mo/users.py
index 98bfa52f2ecf9fc70d181d18f72a4793c41e1422..0754725cac8bc947e871b91f55e936fa6bdfb9a7 100644
--- a/mo/users.py
+++ b/mo/users.py
@@ -427,7 +427,7 @@ def check_activation_token(token: str) -> Optional[db.User]:
         return user
 
 
-def new_reg_request(type: db.RegReqType, client: str) -> Optional[db.RegRequest]:
+def new_reg_request(type: db.RegReqType, client: Optional[str]) -> Optional[db.RegRequest]:
     sess = db.get_session()
 
     # Zatím jen jednoduchý rate limit, časem možno vylepšit
@@ -442,7 +442,7 @@ def new_reg_request(type: db.RegReqType, client: str) -> Optional[db.RegRequest]
         created_at=mo.now,
         expires_at=mo.now + datetime.timedelta(minutes=config.REG_TOKEN_VALIDITY),
         email_token=email_token,
-        client=client,
+        client=client or 'unknown',
     )
 
 
@@ -454,7 +454,7 @@ def expire_reg_requests():
     sess.commit()
 
 
-def request_reset_password(user: db.User, client: str) -> Optional[db.RegRequest]:
+def request_reset_password(user: db.User, client: Optional[str]) -> Optional[db.RegRequest]:
     logger.info('Login: Požadavek na reset hesla pro <%s>', user.email)
     assert not user.is_admin
     rr = new_reg_request(db.RegReqType.reset_passwd, client)