diff --git a/third_party/3/itsdangerous.pyi b/third_party/3/itsdangerous.pyi
index 067fbdd1c..81016f931 100644
--- a/third_party/3/itsdangerous.pyi
+++ b/third_party/3/itsdangerous.pyi
@@ -146,7 +146,7 @@ class TimedJSONWebSignatureSerializer(JSONWebSignatureSerializer):
     def now(self) -> int: ...
 
 class URLSafeSerializerMixin:
-    def load_payload(self, payload: Any, **kwargs) -> Any: ...
+    def load_payload(self, payload: Any, serializer: Any = ..., **kwargs) -> Any: ...
     def dump_payload(self, *args, **kwargs) -> bytes: ...
 
 class URLSafeSerializer(URLSafeSerializerMixin, Serializer):