diff --git a/stdlib/2/__builtin__.pyi b/stdlib/2/__builtin__.pyi
index 5a46deb80..a1d1e49ae 100644
--- a/stdlib/2/__builtin__.pyi
+++ b/stdlib/2/__builtin__.pyi
@@ -139,6 +139,7 @@ class int:
     def __abs__(self) -> int: ...
     def __hash__(self) -> int: ...
     def __nonzero__(self) -> bool: ...
+    def __index__(self) -> int: ...
 
 class float:
     def __init__(self, x: Union[SupportsFloat, str, unicode, bytearray] = ...) -> None: ...
diff --git a/stdlib/2/builtins.pyi b/stdlib/2/builtins.pyi
index 5a46deb80..a1d1e49ae 100644
--- a/stdlib/2/builtins.pyi
+++ b/stdlib/2/builtins.pyi
@@ -139,6 +139,7 @@ class int:
     def __abs__(self) -> int: ...
     def __hash__(self) -> int: ...
     def __nonzero__(self) -> bool: ...
+    def __index__(self) -> int: ...
 
 class float:
     def __init__(self, x: Union[SupportsFloat, str, unicode, bytearray] = ...) -> None: ...
diff --git a/stdlib/3/builtins.pyi b/stdlib/3/builtins.pyi
index 9e1c74f73..cf2a8cdb1 100644
--- a/stdlib/3/builtins.pyi
+++ b/stdlib/3/builtins.pyi
@@ -158,6 +158,7 @@ class int:
     def __abs__(self) -> int: ...
     def __hash__(self) -> int: ...
     def __bool__(self) -> bool: ...
+    def __index__(self) -> int: ...
 
 class float:
     def __init__(self, x: Union[SupportsFloat, str, bytes] = ...) -> None: ...