diff --git a/crud.py b/crud.py
index 4bbde29..de76cce 100644
--- a/crud.py
+++ b/crud.py
@@ -105,7 +105,7 @@ async def get_pay_links(wallet_ids: Union[str, List[str]]) -> List[PayLink]:
 
 
 async def update_pay_link(link_id: str, **kwargs) -> Optional[PayLink]:
-    if len(kwargs["username"]) > 0:
+    if "username" in kwargs and len(kwargs["username"]) > 0:
         await check_lnaddress_format(kwargs["username"])
         await check_lnaddress_not_exists(kwargs["username"])