diff --git a/scenario/context.py b/scenario/context.py
index 5cf51635..7167d14e 100644
--- a/scenario/context.py
+++ b/scenario/context.py
@@ -599,7 +599,7 @@ def _record_status(self, state: "State", is_app: bool):
         else:
             self.unit_status_history.append(state.unit_status)
 
-    def __call__(self, event: Union["_Event", "Action"], state: "State"):
+    def __call__(self, event: Union["_Event", "_Action"], state: "State"):
         """Context manager to introspect live charm object before and after the event is emitted.
 
         Usage::
@@ -619,7 +619,7 @@ def __call__(self, event: Union["_Event", "Action"], state: "State"):
             event: the :class:`Event` or :class:`Action` that the charm will respond to.
             state: the :class:`State` instance to use when handling the Event.
         """
-        if isinstance(event, Action) or event.action:
+        if isinstance(event, _Action) or event.action:
             return _ActionManager(self, event, state)
         return _EventManager(self, event, state)
 
diff --git a/tests/test_context.py b/tests/test_context.py
index f3ad4d16..851e73f4 100644
--- a/tests/test_context.py
+++ b/tests/test_context.py
@@ -4,7 +4,7 @@
 from ops import CharmBase
 
 from scenario import ActionOutput, Context, State
-from scenario.state import _Action, _Event, next_action_id
+from scenario.state import _Event, next_action_id
 
 
 class MyCharm(CharmBase):
@@ -65,7 +65,7 @@ def test_context_manager():
         event.run()
         assert event.charm.meta.name == "foo"
 
-    with ctx(Action("act"), state) as event:
+    with ctx(ctx.on.action("act"), state) as event:
         event.run_action()
         assert event.charm.meta.name == "foo"