diff --git a/stdlib/3/json.pyi b/stdlib/3/json.pyi
index 6accc80ff..63592c338 100644
--- a/stdlib/3/json.pyi
+++ b/stdlib/3/json.pyi
@@ -85,4 +85,4 @@ class JSONDecoder(object):
             strict: bool=True,
             object_pairs_hook: Callable[[List[Tuple[str, Any]]], Any]=None) -> None: ...
     def decode(self, s: str) -> Any: ...
-    def raw_decode(self, s: str) -> Tuple[Any, int]: ...
+    def raw_decode(self, s: str, idx: int=...) -> Tuple[Any, int]: ...