diff --git a/stdlib/3/unittest/__init__.pyi b/stdlib/3/unittest/__init__.pyi
index 15ebff6bf..0755fc4c0 100644
--- a/stdlib/3/unittest/__init__.pyi
+++ b/stdlib/3/unittest/__init__.pyi
@@ -117,7 +117,7 @@ class TestCase:
                     msg: Any = ...) -> None: ...
     def assertNotRegex(self, text: str, regex: Union[str, Pattern[str]],
                        msg: Any = ...) -> None: ...
-    def assertCountEqual(self, first: Sequence[Any], second: Sequence[Any],
+    def assertCountEqual(self, first: Iterable[Any], second: Iterable[Any],
                          msg: Any = ...) -> None: ...
     def addTypeEqualityFunc(self, typeobj: Type[Any],
                             function: Callable[..., None]) -> None: ...