Index: test/c2s-outbox.test.js
===================================================================
--- test/c2s-outbox.test.js	(revision dd568e79b476d730bac4264e3e6d0bab5cfb9753)
+++ test/c2s-outbox.test.js	(revision 4c70ecbe5990b354c76af6b01ef4b3d7e937a63a)
@@ -67,5 +67,6 @@
 
 test('Undo of an unknown inner type → 400', async () => {
-  const out = await AP.ingestOutboxActivity(site, user, { type: 'Undo', object: { type: 'Block', object: 'x' } });
+  // Block used to be the unsupported example; it is real now (c2s-block.test).
+  const out = await AP.ingestOutboxActivity(site, user, { type: 'Undo', object: { type: 'Move', object: 'x' } });
   assert.equal(out.status, 400);
   assert.equal(out.error, 'unsupported_undo');