diff --git a/requirements-tests-py3.txt b/requirements-tests-py3.txt
index f4dab477a..9753eac9e 100644
--- a/requirements-tests-py3.txt
+++ b/requirements-tests-py3.txt
@@ -5,4 +5,4 @@ flake8==3.8.4
 flake8-bugbear==20.1.4
 flake8-pyi==20.10.0
 isort==5.5.3
-pytype>=2021.01.28
+pytype>=2021.4.1
diff --git a/stubs/pkg_resources/pkg_resources/__init__.pyi b/stubs/pkg_resources/pkg_resources/__init__.pyi
index 4f25f73bf..c1adcbb9d 100644
--- a/stubs/pkg_resources/pkg_resources/__init__.pyi
+++ b/stubs/pkg_resources/pkg_resources/__init__.pyi
@@ -38,12 +38,12 @@ class WorkingSet:
         self, plugin_env: Environment, full_env: Optional[Environment] = ..., fallback: bool = ...
     ) -> Tuple[List[Distribution], Dict[Distribution, Exception]]: ...
 
-working_set: WorkingSet
+working_set: WorkingSet = ...
 
-def require(*requirements: _NestedStr) -> Sequence[Distribution]: ...
-def run_script(requires: str, script_name: str) -> None: ...
-def iter_entry_points(group: str, name: Optional[str] = ...) -> Generator[EntryPoint, None, None]: ...
-def add_activation_listener(callback: Callable[[Distribution], None]) -> None: ...
+require = working_set.require
+run_script = working_set.run_script
+iter_entry_points = working_set.iter_entry_points
+add_activation_listener = working_set.subscribe
 
 class Environment:
     def __init__(