diff --git a/packages/SwingSet/test/workers/test-worker.js b/packages/SwingSet/test/workers/test-worker.js
index 854cc677aeb..ea709899487 100644
--- a/packages/SwingSet/test/workers/test-worker.js
+++ b/packages/SwingSet/test/workers/test-worker.js
@@ -15,6 +15,7 @@ maybeTestXS('xs vat manager', async t => {
 
   await c.run();
   t.is(c.bootstrapResult.status(), 'fulfilled');
+  t.deepEqual(c.dump().log, ['testLog works']);
 
   await c.shutdown();
 });
@@ -28,6 +29,7 @@ test.skip('nodeWorker vat manager', async t => {
 
   await c.run();
   t.is(c.bootstrapResult.status(), 'fulfilled');
+  t.deepEqual(c.dump().log, ['testLog works']);
 
   await c.shutdown();
 });
@@ -40,6 +42,7 @@ test('node-subprocess vat manager', async t => {
 
   await c.run();
   t.is(c.bootstrapResult.status(), 'fulfilled');
+  t.deepEqual(c.dump().log, ['testLog works']);
 
   await c.shutdown();
 });
diff --git a/packages/SwingSet/test/workers/vat-target.js b/packages/SwingSet/test/workers/vat-target.js
index 1af1ba458fb..dc28dc030d5 100644
--- a/packages/SwingSet/test/workers/vat-target.js
+++ b/packages/SwingSet/test/workers/vat-target.js
@@ -12,8 +12,11 @@ function ignore(p) {
 // inbound events ('dispatch'), which will provoke a set of outbound events
 // ('syscall'), that cover the full range of the dispatch/syscall interface
 
-export function buildRootObject() {
+export function buildRootObject(vatPowers) {
   console.log(`vat does buildRootObject`); // make sure console works
+  // note: XS doesn't appear to print console.log unless an exception happens
+  vatPowers.testLog('testLog works');
+
   const precB = makePromiseKit();
   const precC = makePromiseKit();
   let callbackObj;