diff --git a/temporalio/worker/_interceptor.py b/temporalio/worker/_interceptor.py
index e2706930..a3146200 100644
--- a/temporalio/worker/_interceptor.py
+++ b/temporalio/worker/_interceptor.py
@@ -388,7 +388,7 @@ async def signal_external_workflow(
 
     def start_activity(
         self, input: StartActivityInput
-    ) -> temporalio.workflow.ActivityHandle:
+    ) -> temporalio.workflow.ActivityHandle[Any]:
         """Called for every :py:func:`temporalio.workflow.start_activity` and
         :py:func:`temporalio.workflow.execute_activity` call.
         """
@@ -396,7 +396,7 @@ def start_activity(
 
     async def start_child_workflow(
         self, input: StartChildWorkflowInput
-    ) -> temporalio.workflow.ChildWorkflowHandle:
+    ) -> temporalio.workflow.ChildWorkflowHandle[Any, Any]:
         """Called for every :py:func:`temporalio.workflow.start_child_workflow`
         and :py:func:`temporalio.workflow.execute_child_workflow` call.
         """
@@ -404,7 +404,7 @@ async def start_child_workflow(
 
     def start_local_activity(
         self, input: StartLocalActivityInput
-    ) -> temporalio.workflow.ActivityHandle:
+    ) -> temporalio.workflow.ActivityHandle[Any]:
         """Called for every :py:func:`temporalio.workflow.start_local_activity`
         and :py:func:`temporalio.workflow.execute_local_activity` call.
         """
diff --git a/temporalio/worker/_workflow_instance.py b/temporalio/worker/_workflow_instance.py
index 4c9e69dd..ec229c71 100644
--- a/temporalio/worker/_workflow_instance.py
+++ b/temporalio/worker/_workflow_instance.py
@@ -1543,12 +1543,10 @@ def _outbound_schedule_activity(
                 "Activity must have start_to_close_timeout or schedule_to_close_timeout"
             )
 
-        handle: Optional[_ActivityHandle] = None
+        handle: _ActivityHandle
 
         # Function that runs in the handle
         async def run_activity() -> Any:
-            nonlocal handle
-            assert handle
             while True:
                 # Mark it as started each loop because backoff could cause it to
                 # be marked as unstarted
@@ -1615,12 +1613,10 @@ async def _outbound_signal_external_workflow(
     async def _outbound_start_child_workflow(
         self, input: StartChildWorkflowInput
     ) -> _ChildWorkflowHandle:
-        handle: Optional[_ChildWorkflowHandle] = None
+        handle: _ChildWorkflowHandle
 
         # Common code for handling cancel for start and run
         def apply_child_cancel_error() -> None:
-            nonlocal handle
-            assert handle
             # Send a cancel request to the child
             cancel_command = self._add_command()
             handle._apply_cancel_command(cancel_command)
@@ -1638,9 +1634,7 @@ def apply_child_cancel_error() -> None:
 
         # Function that runs in the handle
         async def run_child() -> Any:
-            nonlocal handle
             while True:
-                assert handle
                 try:
                     # We have to shield because we don't want the future itself
                     # to be cancelled
@@ -2391,17 +2385,17 @@ async def signal_external_workflow(
 
     def start_activity(
         self, input: StartActivityInput
-    ) -> temporalio.workflow.ActivityHandle:
+    ) -> temporalio.workflow.ActivityHandle[Any]:
         return self._instance._outbound_schedule_activity(input)
 
     async def start_child_workflow(
         self, input: StartChildWorkflowInput
-    ) -> temporalio.workflow.ChildWorkflowHandle:
+    ) -> temporalio.workflow.ChildWorkflowHandle[Any, Any]:
         return await self._instance._outbound_start_child_workflow(input)
 
     def start_local_activity(
         self, input: StartLocalActivityInput
-    ) -> temporalio.workflow.ActivityHandle:
+    ) -> temporalio.workflow.ActivityHandle[Any]:
         return self._instance._outbound_schedule_activity(input)
 
 
diff --git a/tests/helpers/__init__.py b/tests/helpers/__init__.py
index 48eb03f5..da525974 100644
--- a/tests/helpers/__init__.py
+++ b/tests/helpers/__init__.py
@@ -4,7 +4,7 @@
 import uuid
 from contextlib import closing
 from datetime import timedelta
-from typing import Any, Awaitable, Callable, Optional, Sequence, Type, TypeVar, Union
+from typing import Any, Awaitable, Callable, Optional, Sequence, Type, TypeVar
 
 from temporalio.api.common.v1 import WorkflowExecution
 from temporalio.api.enums.v1 import IndexedValueType