diff --git a/contract/package.json b/contract/package.json
index d335604..633570d 100644
--- a/contract/package.json
+++ b/contract/package.json
@@ -46,6 +46,7 @@
   "dependencies": {
     "@agoric/ertp": "^0.16.3-u18.0",
     "@agoric/internal": "^0.4.0-u18.0",
+    "@agoric/vat-data": "0.5.3-u18.1",
     "@agoric/vats": "^0.16.0-u18.0",
     "@agoric/zoe": "^0.26.3-u18.0",
     "@agoric/zone": "^0.3.0-u18.1",
diff --git a/contract/src/offer-up.contract.js b/contract/src/offer-up.contract.js
index 09cfbb0..5581f0d 100644
--- a/contract/src/offer-up.contract.js
+++ b/contract/src/offer-up.contract.js
@@ -79,7 +79,7 @@ harden(customTermsShape);
  *
  * @param {ZCF<OfferUpTerms>} zcf
  * @param {*} _privateArgs
- * @param {import('@agoric/ertp').Baggage} baggage
+ * @param {import('@agoric/vat-data').Baggage} baggage
  */
 export const start = async (zcf, _privateArgs, baggage) => {
   const { tradePrice, maxItems = 3n } = zcf.getTerms();
diff --git a/yarn.lock b/yarn.lock
index 62e49bb..8e87982 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -63,7 +63,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@agoric/base-zone@npm:0.1.1-upgrade-18-dev-ef001c0.0+ef001c0":
+"@agoric/base-zone@npm:0.1.1-upgrade-18-dev-ef001c0.0+ef001c0, @agoric/base-zone@npm:^0.1.1-u18.1":
   version: 0.1.1-upgrade-18-dev-ef001c0.0
   resolution: "@agoric/base-zone@npm:0.1.1-upgrade-18-dev-ef001c0.0"
   dependencies:
@@ -621,7 +621,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@agoric/store@npm:0.9.3-upgrade-18-dev-ef001c0.0+ef001c0, @agoric/store@npm:^0.9.3-u16.0":
+"@agoric/store@npm:0.9.3-upgrade-18-dev-ef001c0.0+ef001c0, @agoric/store@npm:^0.9.3-u16.0, @agoric/store@npm:^0.9.3-u18.1":
   version: 0.9.3-upgrade-18-dev-ef001c0.0
   resolution: "@agoric/store@npm:0.9.3-upgrade-18-dev-ef001c0.0"
   dependencies:
@@ -718,7 +718,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@agoric/swingset-liveslots@npm:0.10.3-upgrade-18-dev-ef001c0.0+ef001c0":
+"@agoric/swingset-liveslots@npm:0.10.3-upgrade-18-dev-ef001c0.0+ef001c0, @agoric/swingset-liveslots@npm:^0.10.3-u18.1":
   version: 0.10.3-upgrade-18-dev-ef001c0.0
   resolution: "@agoric/swingset-liveslots@npm:0.10.3-upgrade-18-dev-ef001c0.0"
   dependencies:
@@ -1014,6 +1014,20 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@agoric/vat-data@npm:0.5.3-u18.1":
+  version: 0.5.3-u18.1
+  resolution: "@agoric/vat-data@npm:0.5.3-u18.1"
+  dependencies:
+    "@agoric/base-zone": "npm:^0.1.1-u18.1"
+    "@agoric/store": "npm:^0.9.3-u18.1"
+    "@agoric/swingset-liveslots": "npm:^0.10.3-u18.1"
+    "@endo/errors": "npm:^1.2.8"
+    "@endo/exo": "npm:^1.5.7"
+    "@endo/patterns": "npm:^1.4.7"
+  checksum: 10c0/8c3b428ec517683f4efc9b51374fb7f68de02b0b5533591cbd2f7b13c056e824f75085e5cfe438a11442c1880055b07ebbd6a7adf2057372bc2c98e4cfa4ca0c
+  languageName: node
+  linkType: hard
+
 "@agoric/vat-data@npm:0.5.3-upgrade-18-dev-cc4b6b8.0+cc4b6b8":
   version: 0.5.3-upgrade-18-dev-cc4b6b8.0
   resolution: "@agoric/vat-data@npm:0.5.3-upgrade-18-dev-cc4b6b8.0"
@@ -12546,6 +12560,7 @@ __metadata:
     "@agoric/ertp": "npm:^0.16.3-u18.0"
     "@agoric/eslint-config": "npm:^0.4.1-u16.0"
     "@agoric/internal": "npm:^0.4.0-u18.0"
+    "@agoric/vat-data": "npm:0.5.3-u18.1"
     "@agoric/vats": "npm:^0.16.0-u18.0"
     "@agoric/zoe": "npm:^0.26.3-u18.0"
     "@agoric/zone": "npm:^0.3.0-u18.1"