diff --git a/turbopack/crates/turbo-tasks-testing/tests/detached.rs b/turbopack/crates/turbo-tasks-testing/tests/detached.rs
index e738d43ae76f0..b8210b269b912 100644
--- a/turbopack/crates/turbo-tasks-testing/tests/detached.rs
+++ b/turbopack/crates/turbo-tasks-testing/tests/detached.rs
@@ -2,9 +2,9 @@
 
 use tokio::{
     sync::{watch, Notify},
-    time::{timeout, Duration},
+    time::{sleep, timeout, Duration},
 };
-use turbo_tasks::{turbo_tasks, Completion, TransientInstance, Vc};
+use turbo_tasks::{turbo_tasks, State, TransientInstance, Vc};
 use turbo_tasks_testing::{register, run, Registration};
 
 static REGISTRATION: Registration = register!();
@@ -12,37 +12,41 @@ static REGISTRATION: Registration = register!();
 #[tokio::test]
 async fn test_spawns_detached() -> anyhow::Result<()> {
     run(&REGISTRATION, || async {
-        let notify = TransientInstance::new(Notify::new());
-        let (tx, mut rx) = watch::channel(None);
+        timeout(Duration::from_secs(5), async {
+            let notify = TransientInstance::new(Notify::new());
+            let (tx, mut rx) = watch::channel(None);
+            let tx = TransientInstance::new(tx);
 
-        // create the task
-        let out_vc = spawns_detached(notify.clone(), TransientInstance::new(tx));
+            // create the task
+            let out_vc = spawns_detached(notify.clone(), tx.clone());
 
-        // see that the task does not exit yet
-        timeout(Duration::from_millis(100), out_vc.strongly_consistent())
-            .await
-            .expect_err("should wait on the detached task");
+            // see that the task does not exit yet
+            timeout(Duration::from_millis(100), out_vc.strongly_consistent())
+                .await
+                .expect_err("should wait on the detached task");
 
-        // let the detached future exit
-        notify.notify_waiters();
+            // let the detached future exit
+            notify.notify_waiters();
 
-        // it should send us back a cell
-        let detached_vc: Vc<u32> = rx.wait_for(|opt| opt.is_some()).await.unwrap().unwrap();
-        assert_eq!(*detached_vc.await.unwrap(), 42);
+            // it should send us back a cell
+            let detached_vc: Vc<u32> = rx.wait_for(|opt| opt.is_some()).await?.unwrap();
+            assert_eq!(*detached_vc.strongly_consistent().await?, 42);
 
-        // the parent task should now be able to exit
-        out_vc.strongly_consistent().await.unwrap();
+            // the parent task should now be able to exit
+            out_vc.strongly_consistent().await?;
 
-        Ok(())
+            Ok(())
+        })
+        .await?
     })
     .await
 }
 
 #[turbo_tasks::function]
-fn spawns_detached(
+async fn spawns_detached(
     notify: TransientInstance<Notify>,
     sender: TransientInstance<watch::Sender<Option<Vc<u32>>>>,
-) -> Vc<Completion> {
+) -> Vc<()> {
     tokio::spawn(turbo_tasks().detached_for_testing(Box::pin(async move {
         notify.notified().await;
         // creating cells after the normal lifetime of the task should be okay, as the parent task
@@ -50,5 +54,88 @@ fn spawns_detached(
         sender.send(Some(Vc::cell(42))).unwrap();
         Ok(())
     })));
-    Completion::new()
+    Vc::cell(())
+}
+
+#[tokio::test]
+async fn test_spawns_detached_changing() -> anyhow::Result<()> {
+    run(&REGISTRATION, || async {
+        timeout(Duration::from_secs(5), async {
+            let (tx, mut rx) = watch::channel(None);
+            let tx = TransientInstance::new(tx);
+
+            // state that's read by the detached future
+            let changing_input_detached = ChangingInput {
+                state: State::new(42),
+            }
+            .cell();
+
+            // state that's read by the outer task
+            let changing_input_outer = ChangingInput {
+                state: State::new(0),
+            }
+            .cell();
+
+            // create the task
+            let out_vc =
+                spawns_detached_changing(tx.clone(), changing_input_detached, changing_input_outer);
+
+            // it should send us back a cell
+            let detached_vc: Vc<u32> = rx.wait_for(|opt| opt.is_some()).await.unwrap().unwrap();
+            assert_eq!(*detached_vc.strongly_consistent().await.unwrap(), 42);
+
+            // the parent task should now be able to exit
+            out_vc.strongly_consistent().await.unwrap();
+
+            // changing either input should invalidate the vc and cause it to run again
+            changing_input_detached.await.unwrap().state.set(43);
+            out_vc.strongly_consistent().await.unwrap();
+            assert_eq!(*detached_vc.strongly_consistent().await.unwrap(), 43);
+
+            changing_input_outer.await.unwrap().state.set(44);
+            assert_eq!(*out_vc.strongly_consistent().await.unwrap(), 44);
+
+            Ok(())
+        })
+        .await?
+    })
+    .await
+}
+
+#[turbo_tasks::value]
+struct ChangingInput {
+    state: State<u32>,
+}
+
+#[turbo_tasks::function]
+async fn spawns_detached_changing(
+    sender: TransientInstance<watch::Sender<Option<Vc<u32>>>>,
+    changing_input_detached: Vc<ChangingInput>,
+    changing_input_outer: Vc<ChangingInput>,
+) -> Vc<u32> {
+    let tt = turbo_tasks();
+    tokio::spawn(tt.clone().detached_for_testing(Box::pin(async move {
+        sleep(Duration::from_millis(100)).await;
+        // nested detached_for_testing calls should work
+        tokio::spawn(tt.clone().detached_for_testing(Box::pin(async move {
+            sleep(Duration::from_millis(100)).await;
+            // creating cells after the normal lifetime of the task should be okay, as the parent
+            // task is waiting on us before exiting!
+            sender
+                .send(Some(Vc::cell(
+                    *read_changing_input(changing_input_detached).await.unwrap(),
+                )))
+                .unwrap();
+            Ok(())
+        })));
+        Ok(())
+    })));
+    Vc::cell(*read_changing_input(changing_input_outer).await.unwrap())
+}
+
+// spawns_detached should take a dependency on this function for each input
+#[turbo_tasks::function]
+async fn read_changing_input(changing_input: Vc<ChangingInput>) -> Vc<u32> {
+    // when changing_input.set is called, it will trigger an invalidator for this task
+    Vc::cell(*changing_input.await.unwrap().state.get())
 }