1 files changed, 2 insertions, 1 deletions
diff --git a/ext/wasm/demo-worker1.js b/ext/wasm/demo-worker1.js
index 2da80bc23..ac4e9f423 100644
--- a/ext/wasm/demo-worker1.js
+++ b/ext/wasm/demo-worker1.js
@@ -291,7 +291,8 @@
       log("open result",ev);
       T.assert('testing2.sqlite3'===ev.result.filename)
         .assert(ev.dbId)
-        .assert(ev.messageId);
+        .assert(ev.messageId)
+        .assert('string' === typeof ev.result.vfs);
       DbState.id = ev.dbId;
       if(waitForOpen) setTimeout(runTests2, 0);
     });