diff --git a/packages/SwingSet/src/kernel/state/vatKeeper.js b/packages/SwingSet/src/kernel/state/vatKeeper.js
index bd15830d7fb5..1d4d6b1f12f4 100644
--- a/packages/SwingSet/src/kernel/state/vatKeeper.js
+++ b/packages/SwingSet/src/kernel/state/vatKeeper.js
@@ -182,11 +182,11 @@ export function makeVatKeeper(
     const key = `${vatID}.vatParameters`;
     // increment-before-decrement to minimize spurious rc=0 checks
     for (const kref of newVPCD.slots) {
-      incrementRefCount(kref, `${vatID}.vp`);
+      incrementRefCount(kref, `${vatID}.vatParameters`);
     }
     const old = kvStore.get(key) || '{"slots":[]}';
     for (const kref of JSON.parse(old).slots) {
-      decrementRefCount(kref, `${vatID}.vp`);
+      decrementRefCount(kref, `${vatID}.vatParameters`);
     }
     kvStore.set(key, JSON.stringify(newVPCD));
   }