diff --git a/stdlib/2/__builtin__.pyi b/stdlib/2/__builtin__.pyi
index 59b01e58a..83e6c29be 100644
--- a/stdlib/2/__builtin__.pyi
+++ b/stdlib/2/__builtin__.pyi
@@ -470,9 +470,9 @@ class slice(object):
     step = ...  # type: Optional[int]
     stop = ...  # type: Optional[int]
     @overload
-    def __init__(self, stop: int = None) -> None: ...
+    def __init__(self, stop: Optional[int]) -> None: ...
     @overload
-    def __init__(self, start: int = None, stop: int = None, step: int = None) -> None: ...
+    def __init__(self, start: Optional[int], stop: Optional[int], step: int = None) -> None: ...
 
 class tuple(Sequence[_T_co], Generic[_T_co]):
     def __init__(self, iterable: Iterable[_T_co] = ...) -> None: ...
diff --git a/stdlib/3/builtins.pyi b/stdlib/3/builtins.pyi
index 3c82247a6..185ee8163 100644
--- a/stdlib/3/builtins.pyi
+++ b/stdlib/3/builtins.pyi
@@ -517,9 +517,9 @@ class slice:
     step = ...  # type: Optional[int]
     stop = ...  # type: Optional[int]
     @overload
-    def __init__(self, stop: int = None) -> None: ...
+    def __init__(self, stop: Optional[int]) -> None: ...
     @overload
-    def __init__(self, start: int = None, stop: int = None, step: int = None) -> None: ...
+    def __init__(self, start: Optional[int], stop: Optional[int], step: int = None) -> None: ...
 
 class tuple(Sequence[_T_co], Generic[_T_co]):
     def __init__(self, iterable: Iterable[_T_co] = ...) -> None: ...