diff --git a/apps/desktop/src/components/assistant-ui/thread/user-edit-composer.tsx b/apps/desktop/src/components/assistant-ui/thread/user-edit-composer.tsx
index a61409b3ae..cd0d45eb34 100644
--- a/apps/desktop/src/components/assistant-ui/thread/user-edit-composer.tsx
+++ b/apps/desktop/src/components/assistant-ui/thread/user-edit-composer.tsx
@@ -140,6 +140,11 @@ export const UserEditComposer: FC<UserEditComposerProps> = ({ cwd, gateway, sess
   // bus leaks: confirming or cancelling an edit tears the composer down while
   // `'edit'` is still the active target. Release it alongside the thread-scroll
   // cleanup so keyboard routing falls back to the visible chat composer.
+  //
+  // It also drains whatever `scheduleTimeout` still has pending, which is a
+  // second concern under the same heading rather than a separate one: both
+  // are "this composer is going away", they unmount together by definition,
+  // and a sibling unmount-only effect would only be a second place to forget.
   useEffect(
     () => () => {
       notifyThreadEditClose()
diff --git a/apps/desktop/src/components/assistant-ui/thread/user-message-edit.test.tsx b/apps/desktop/src/components/assistant-ui/thread/user-message-edit.test.tsx
index 5befc0515d..98449a0cb3 100644
--- a/apps/desktop/src/components/assistant-ui/thread/user-message-edit.test.tsx
+++ b/apps/desktop/src/components/assistant-ui/thread/user-message-edit.test.tsx
@@ -263,9 +263,13 @@ describe('Enter submission and latch behavior', () => {
       return id
     }) as typeof window.setTimeout)
 
-    vi.spyOn(window, 'clearTimeout').mockImplementation(((id?: number) => {
+    // `id` is typed `unknown` for the same reason the arrays above are: what
+    // actually arrives is whatever `setTimeout` returned, and under jsdom that
+    // is a Timeout object rather than the `number` the DOM lib promises.
+    // Declaring it `number` would have documented a shape this never sees.
+    vi.spyOn(window, 'clearTimeout').mockImplementation(((id?: unknown) => {
       cleared.push(id)
-      realClearTimeout(id)
+      realClearTimeout(id as number | undefined)
     }) as typeof window.clearTimeout)
 
     const onEdit = vi.fn(async () => {})