diff --git a/stdlib/3/concurrent/futures/_base.pyi b/stdlib/3/concurrent/futures/_base.pyi
index 27c2711fe..00ef5b6c3 100644
--- a/stdlib/3/concurrent/futures/_base.pyi
+++ b/stdlib/3/concurrent/futures/_base.pyi
@@ -27,10 +27,10 @@ class Future(Generic[_T]):
     def done(self) -> bool: ...
     def add_done_callback(self, fn: Callable[[Future], Any]) -> None: ...
     def result(self, timeout: Optional[float] = ...) -> _T: ...
-    def exception(self, timeout: Optional[float] = ...) -> Exception: ...
+    def exception(self, timeout: Optional[float] = ...) -> BaseException: ...
     def set_running_or_notify_cancel(self) -> None: ...
     def set_result(self, result: _T) -> None: ...
-    def set_exception(self, exception: Exception) -> None: ...
+    def set_exception(self, exception: BaseException) -> None: ...
 
 class Executor:
     def submit(self, fn: Callable[..., _T], *args: Any, **kwargs: Any) -> Future[_T]: ...
diff --git a/third_party/2/concurrent/futures/__init__.pyi b/third_party/2/concurrent/futures/__init__.pyi
index 8e915ae27..492ee1bfa 100644
--- a/third_party/2/concurrent/futures/__init__.pyi
+++ b/third_party/2/concurrent/futures/__init__.pyi
@@ -8,12 +8,12 @@ class Future(Generic[_T]):
     def running(self) -> bool: ...
     def done(self) -> bool: ...
     def result(self, timeout: float = ...) -> _T: ...
-    def exception(self, timeout: float = ...) -> Exception: ...
+    def exception(self, timeout: float = ...) -> BaseException: ...
     def add_done_callback(self, fn: Callable[[Future], Any]) -> None: ...
 
     def set_running_or_notify_cancel(self) -> None: ...
     def set_result(self, result: _T) -> None: ...
-    def set_exception(self, exception: Exception) -> None: ...
+    def set_exception(self, exception: BaseException) -> None: ...
 
 class Executor:
     def submit(self, fn: Callable[..., _T], *args: Any, **kwargs: Any) -> Future[_T]: ...