diff --git a/modules/mesh-delivery-indexer/internal/index/pending_test.go b/modules/mesh-delivery-indexer/internal/index/pending_test.go
index 29da34be..2e338117 100644
--- a/modules/mesh-delivery-indexer/internal/index/pending_test.go
+++ b/modules/mesh-delivery-indexer/internal/index/pending_test.go
@@ -292,6 +292,27 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 			t.Errorf("said %v, want %v", b.events(), want)
 		}
 	})
+	t.Run("IX22 a merged revision naming a newer indexer is the previous catalog graph revision with only the indexer's entry replaced", func(t *testing.T) { // design 47 G §273, §237
+		b := newTakeInBed(t)
+		store := newMemObjects(0)
+		b.ix.Revisions = store
+		if err := b.ix.KeepView(ctx); err != nil {
+			t.Fatal(err)
+		}
+		before, _, err := newestTrunk(ctx, store)
+		if err != nil || before.Revision != 1 {
+			t.Fatalf("the view's revision %+v (%v), want revision 1", before, err)
+		}
+		// The merge changes avahi and the indexer: only the indexer is written, the revision is made at once.
+		b.arrive(t, 2, b.merge(21, sha('c'), "tree-avahi-3", "tree-indexer-2"))
+		after, _, err := newestTrunk(ctx, store)
+		if err != nil || after.Revision != 2 {
+			t.Fatalf("after the merge naming a newer indexer the newest revision is %+v (%v), want revision 2", after, err)
+		}
+		if changed := changedEntries(before.Entries, after.Entries); !slices.Equal(changed, []string{Module}) {
+			t.Errorf("the revision differs from the previous in %v, want the indexer's entry alone", changed)
+		}
+	})
 	t.Run("P1 a revision that adds a Go module its own indexer uses is computed against that module's packages at its merge", func(t *testing.T) {
 		// The Go module exists only at the revision's own merge: nothing publishes it before the take-in, so the fingerprint
 		// the revision names must come from the packages its merge holds (issue 1585, ADR 0593 §2), not wait for a version only