diff --git a/third_party/2and3/attr/validators.pyi b/third_party/2and3/attr/validators.pyi
index 477bac91c..3fc34377c 100644
--- a/third_party/2and3/attr/validators.pyi
+++ b/third_party/2and3/attr/validators.pyi
@@ -1,9 +1,9 @@
-from typing import Container, List, Union, TypeVar, Type, Any, Optional
+from typing import Container, List, Union, TypeVar, Type, Any, Optional, Tuple
 from . import _ValidatorType
 
 _T = TypeVar('_T')
 
-def instance_of(type: Type[_T]) -> _ValidatorType[_T]: ...
+def instance_of(type: Union[Tuple[Type[_T], ...], Type[_T]]) -> _ValidatorType[_T]: ...
 def provides(interface: Any) -> _ValidatorType[Any]: ...
 def optional(validator: Union[_ValidatorType[_T], List[_ValidatorType[_T]]]) -> _ValidatorType[Optional[_T]]: ...
 def in_(options: Container[_T]) -> _ValidatorType[_T]: ...