diff --git a/stdlib/2/collections.pyi b/stdlib/2/collections.pyi
index 1fab27443..e0d983ea6 100644
--- a/stdlib/2/collections.pyi
+++ b/stdlib/2/collections.pyi
@@ -67,7 +67,7 @@ class Counter(Dict[_T, int], Generic[_T]):
     @overload
     def __init__(self, iterable: Iterable[_T]) -> None: ...
     def elements(self) -> Iterator[_T]: ...
-    def most_common(self, n: int = ...) -> List[_T]: ...
+    def most_common(self, n: Optional[int] = ...) -> List[Tuple[_T, int]]: ...
     @overload
     def subtract(self, __mapping: Mapping[_T, int]) -> None: ...
     @overload
diff --git a/stdlib/3/collections/__init__.pyi b/stdlib/3/collections/__init__.pyi
index e10d86183..fd6bfd824 100644
--- a/stdlib/3/collections/__init__.pyi
+++ b/stdlib/3/collections/__init__.pyi
@@ -125,7 +125,7 @@ class Counter(Dict[_T, int], Generic[_T]):
 
     def elements(self) -> Iterator[_T]: ...
 
-    def most_common(self, n: int = ...) -> List[_T]: ...
+    def most_common(self, n: Optional[int] = ...) -> List[Tuple[_T, int]]: ...
 
     @overload
     def subtract(self, __mapping: Mapping[_T, int]) -> None: ...