diff --git a/packages/zoe/src/contracts/transferable-counter.js b/packages/zoe/src/contracts/transferable-counter.js
index aea56617ed71..d6f6fcca980f 100644
--- a/packages/zoe/src/contracts/transferable-counter.js
+++ b/packages/zoe/src/contracts/transferable-counter.js
@@ -54,7 +54,7 @@ export const start = async (zcf, privateArgs, instanceBaggage) => {
 
       incr() {
         const count = instanceBaggage.get('count') + 1n;
-        instanceBaggage.set(count);
+        instanceBaggage.set('count', count);
         return count;
       },