diff --git a/companion/codex_display/hook_events.py b/companion/codex_display/hook_events.py
index 1528a5e..a02c81c 100644
--- a/companion/codex_display/hook_events.py
+++ b/companion/codex_display/hook_events.py
@@ -88,15 +88,23 @@ async def process_event(self, event: Dict[str, object]) -> None:
             )
         else:
             existing = self._turns.get(key)
-            self._turns[key] = PendingTurn(
-                turn_id=turn_id,
-                transcript_path=path or (
-                    existing.transcript_path if existing is not None else None
-                ),
-                phase="pending_stop",
-                created_at=existing.created_at if existing is not None else now,
-                counted=existing.counted if existing is not None else False,
+            resolved_path = path or (
+                existing.transcript_path if existing is not None else None
             )
+            if resolved_path is None:
+                self._turns.pop(key, None)
+            else:
+                self._turns[key] = PendingTurn(
+                    turn_id=turn_id,
+                    transcript_path=resolved_path,
+                    phase="pending_stop",
+                    created_at=(
+                        existing.created_at if existing is not None else now
+                    ),
+                    counted=(
+                        existing.counted if existing is not None else False
+                    ),
+                )
         await self._on_change()
 
     async def reconcile(self, now: Optional[float] = None) -> None:
diff --git a/companion/tests/test_hook_events.py b/companion/tests/test_hook_events.py
index d980e09..9c76732 100644
--- a/companion/tests/test_hook_events.py
+++ b/companion/tests/test_hook_events.py
@@ -49,6 +49,18 @@ async def test_stop_waits_for_matching_task_complete(self):
         await self.tracker.reconcile()
         self.assertEqual(self.tracker.extra_count(set()), 0)
 
+    async def test_pathless_stop_clears_sidechat_immediately(self):
+        submit = self._event("UserPromptSubmit")
+        submit["transcript_path"] = None
+        await self.tracker.process_event(submit)
+        self.assertEqual(self.tracker.extra_count(set()), 1)
+
+        stop = self._event("Stop")
+        stop["transcript_path"] = None
+        await self.tracker.process_event(stop)
+
+        self.assertEqual(self.tracker.extra_count(set()), 0)
+
     async def test_unconfirmed_submit_expires(self):
         tracker = HookActivityTracker(
             self.changed,