diff --git a/cmd/mesh-host/nodeagent_integration_test.go b/cmd/mesh-host/nodeagent_integration_test.go
index 4243082..ba61810 100644
--- a/cmd/mesh-host/nodeagent_integration_test.go
+++ b/cmd/mesh-host/nodeagent_integration_test.go
@@ -700,6 +700,8 @@ func (r *recordingRuntime) moved(container string) []string {
 // its changed file and records the server as the bus module's, and asks the container runtime to remove, make, stop,
 // rename or restart nothing, since the build does not change the server. A later want whose build changes the server
 // replaces it once, as any module's, once the want carries the yes (§2: the assigner gives it from the release's Approve).
+// ADR 0601 §2: the bus module keeps data (its streams), so before each of those applies the node agent asks its node's
+// backup seat to back it up, as for every module that keeps data, and applies only once the backup says it is done.
 func TestNatsTheBusServerIsTakenOverAndReplacedOnlyWhenItsBuildChangesIt(t *testing.T) {
 	b := newItBed(t)
 	runtime := &recordingRuntime{containers: map[string]string{}}
@@ -749,7 +751,8 @@ func TestNatsTheBusServerIsTakenOverAndReplacedOnlyWhenItsBuildChangesIt(t *test
 	kvOf(link.PackagesBucket)
 	// The bus module at a build, done: its manifest written and the indexer's module naming it at fp.
 	publish := func(fp, env string) {
-		man := `{"module":"nats","version":"1","provides":[{"name":"mesh-bus","scope":"mesh"}],"resources":[` +
+		man := `{"module":"nats","version":"1","provides":[{"name":"mesh-bus","scope":"mesh"}],` +
+			`"data":{"own":[{"id":"jetstream","path":"` + b.dir + `","class":"valuable","why":"the bus's streams"}]},"resources":[` +
 			`{"id":"server-conf","type":"file","path":"` + conf + `","mode":"0644","content":"listen: new\n"},` +
 			`{"id":"server","type":"container","name":"` + server + `","image":"` + image + `"` + env + `}]}`
 		digest := delivery.ManifestDigest([]byte(man))
@@ -790,6 +793,33 @@ func TestNatsTheBusServerIsTakenOverAndReplacedOnlyWhenItsBuildChangesIt(t *test
 			t.Fatal(err)
 		}
 	}
+	// The node's backup seat: its holder says the bus module has something to back up, starts a backup on now, and says
+	// when it ended on its event; each ask of now notes what the bus's file held then, so the order is seen.
+	var backups []string
+	var backupsMu sync.Mutex
+	if _, err := b.conn.Subscribe(link.SeatToolSubject("node-backup", "backed-up", itNode), func(m *nats.Msg) {
+		_ = m.Respond([]byte(`{"result":[{"module":"nats","runs":1}]}`))
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := b.conn.Subscribe(link.SeatToolSubject("node-backup", "now", itNode), func(m *nats.Msg) {
+		got, _ := os.ReadFile(conf)
+		backupsMu.Lock()
+		backups = append(backups, string(got))
+		backupsMu.Unlock()
+		_ = m.Respond([]byte(`{"result":{"started":true}}`))
+		go func() {
+			time.Sleep(20 * time.Millisecond)
+			_ = b.conn.Publish(backedUpEvent, backupEvent(itNode, "nats", true, time.Now(), ""))
+		}()
+	}); err != nil {
+		t.Fatal(err)
+	}
+	backedUp := func() []string {
+		backupsMu.Lock()
+		defer backupsMu.Unlock()
+		return append([]string(nil), backups...)
+	}
 	first := fpIt("e")
 	publish(first, "")
 	busWant(delivery.Want{FP: first, Self: true})
@@ -809,6 +839,9 @@ func TestNatsTheBusServerIsTakenOverAndReplacedOnlyWhenItsBuildChangesIt(t *test
 	if moved := runtime.moved(server); len(moved) != 0 || runtime.containers[server] != made {
 		t.Fatalf("the first want moved the bus server its build does not change: %v", moved)
 	}
+	if got := backedUp(); len(got) != 1 || got[0] != "listen: old\n" {
+		t.Fatalf("the bus module's first apply was not backed up first: the backups saw %q", got)
+	}
 	state, err := store.Load(b.opts.state)
 	if err != nil {
 		t.Fatal(err)
@@ -835,6 +868,9 @@ func TestNatsTheBusServerIsTakenOverAndReplacedOnlyWhenItsBuildChangesIt(t *test
 			runs++
 		}
 	}
+	if got := backedUp(); len(got) != 2 || got[1] != "listen: new\n" {
+		t.Errorf("the replacing apply of the bus module was not backed up first: the backups saw %q", got)
+	}
 	if runs != 1 || runtime.containers[server] == made {
 		t.Errorf("the build that changes the server made it %d times, its spec still the folded one %v: %v", runs,
 			runtime.containers[server] == made, runtime.moved(server))