diff --git a/nexus/src/app/instance.rs b/nexus/src/app/instance.rs
index 359b333dbb2..8755a797808 100644
--- a/nexus/src/app/instance.rs
+++ b/nexus/src/app/instance.rs
@@ -950,9 +950,14 @@ impl super::Nexus {
                         },
                     )
                     .await
-                    .map(|res| res.into_inner().updated_runtime.map(Into::into))
+                    .map(|res| res.into_inner())
+                    .map(|res| {
+                        (
+                            res.updated_runtime.map(Into::into),
+                            res.expect_callback_in_seconds,
+                        )
+                    })
                     .map_err(|e| SledAgentInstancePutError(e));
-
                 // If the operation succeeded, write the instance state back,
                 // returning any subsequent errors that occurred during that
                 // write.
@@ -965,14 +970,8 @@ impl super::Nexus {
                 // (We later asynchronously receive a cpapi call that invokes
                 // write_returned_instance_state with the outcome.)
                 match instance_put_result {
-                    Ok(state) => {
-                        if state.is_none()
-                            && matches!(
-                                requested,
-                                InstanceStateChangeRequest::Run
-                                    | InstanceStateChangeRequest::Migrate(..)
-                            )
-                        {
+                    Ok((state, callback_timeout)) => {
+                        if let Some(timeout_secs) = callback_timeout {
                             // TODO: This is fragile -- suppose the nexus with
                             // this task crashes *and* the instance creation
                             // happens to also hang. The new nexus won't know
@@ -991,8 +990,10 @@ impl super::Nexus {
                                 .log
                                 .new(o!("component" => "Instance timeout"));
                             tokio::spawn(async move {
-                                tokio::time::sleep(Duration::from_secs(120))
-                                    .await;
+                                tokio::time::sleep(Duration::from_secs_f64(
+                                    timeout_secs,
+                                ))
+                                .await;
                                 if let Some(db_datastore) =
                                     db_datastore_weak.upgrade()
                                 {