diff --git a/stdlib/2/__builtin__.pyi b/stdlib/2/__builtin__.pyi
index 2d8da1561..59b01e58a 100644
--- a/stdlib/2/__builtin__.pyi
+++ b/stdlib/2/__builtin__.pyi
@@ -68,6 +68,8 @@ class type(object):
     # implementation seems to be returning a list.
     def mro(self) -> List[type]: ...
     def __subclasses__(self: _TT) -> List[_TT]: ...
+    def __instancecheck__(self, instance: Any) -> bool: ...
+    def __subclasscheck__(self, subclass: type) -> bool: ...
 
 class int(SupportsInt, SupportsFloat, SupportsAbs[int]):
     @overload
diff --git a/stdlib/3/builtins.pyi b/stdlib/3/builtins.pyi
index 2c1200dfa..952cb3dec 100644
--- a/stdlib/3/builtins.pyi
+++ b/stdlib/3/builtins.pyi
@@ -72,6 +72,8 @@ class type:
     # Note: the documentation doesnt specify what the return type is, the standard
     # implementation seems to be returning a list.
     def mro(self) -> List[type]: ...
+    def __instancecheck__(self, instance: Any) -> bool: ...
+    def __subclasscheck__(self, subclass: type) -> bool: ...
 
 class super(object):
     @overload