diff --git a/packages/orchestration/package.json b/packages/orchestration/package.json
index 91fffe2fc3f..1567a6550da 100644
--- a/packages/orchestration/package.json
+++ b/packages/orchestration/package.json
@@ -48,6 +48,7 @@
     "@agoric/zoe": "^0.26.2",
     "@agoric/zone": "^0.2.2",
     "@endo/base64": "^1.0.5",
+    "@endo/errors": "^1.2.2",
     "@endo/far": "^1.1.2",
     "@endo/marshal": "^1.5.0",
     "@endo/patterns": "^1.4.0"
diff --git a/packages/orchestration/src/utils/packet.js b/packages/orchestration/src/utils/packet.js
index d9c7abdeba4..9f5158abd59 100644
--- a/packages/orchestration/src/utils/packet.js
+++ b/packages/orchestration/src/utils/packet.js
@@ -1,3 +1,4 @@
+import { Fail } from '@endo/errors';
 import { TxBody } from '@agoric/cosmic-proto/cosmos/tx/v1beta1/tx.js';
 import { Any } from '@agoric/cosmic-proto/google/protobuf/any.js';
 import { RequestQuery } from '@agoric/cosmic-proto/tendermint/abci/types.js';
@@ -84,7 +85,7 @@ export function parseTxPacket(response) {
   const { result, error } = JSON.parse(response);
   if (result) return result;
   else if (error) throw Error(error);
-  else throw Error(response);
+  else throw Fail`expected either result or error: ${response}`;
 }
 harden(parseTxPacket);
 
diff --git a/packages/orchestration/test/service.test.ts b/packages/orchestration/test/service.test.ts
index b2829f146f2..a3e6febfabc 100644
--- a/packages/orchestration/test/service.test.ts
+++ b/packages/orchestration/test/service.test.ts
@@ -56,7 +56,7 @@ test('makeICQConnection returns an ICQConnection', async t => {
         ),
       ]),
     ),
-    { message: /"data":"(.*)"memo":""/ },
+    { message: /\\"data\\":\\"(.*)\\"memo\\":\\"\\"/ },
     'TODO do not use echo connection',
   );
 });
@@ -118,7 +118,7 @@ test('makeAccount returns a ChainAccount', async t => {
   );
   await t.throwsAsync(
     heapVowTools.when(E(account).executeEncodedTx([delegateMsg])),
-    { message: /"type":1(.*)"data":"(.*)"memo":""/ },
+    { message: /\\"type\\":1(.*)\\"data\\":\\"(.*)\\"memo\\":\\"\\"/ },
     'TODO do not use echo connection',
   );
 
diff --git a/packages/orchestration/test/utils/packet.test.ts b/packages/orchestration/test/utils/packet.test.ts
index 95c72b475f3..dc461aa26da 100644
--- a/packages/orchestration/test/utils/packet.test.ts
+++ b/packages/orchestration/test/utils/packet.test.ts
@@ -85,7 +85,7 @@ test('parseTxPacket', t => {
   t.throws(
     () => parseTxPacket('{"foo":"bar"}'),
     {
-      message: '{"foo":"bar"}',
+      message: 'expected either result or error: "{\\"foo\\":\\"bar\\"}"',
     },
     'returns original string as error if `result` is not found',
   );
@@ -187,7 +187,7 @@ test('parseQueryPacket', t => {
   t.throws(
     () => parseQueryPacket('{"foo":"bar"}'),
     {
-      message: '{"foo":"bar"}',
+      message: 'expected either result or error: "{\\"foo\\":\\"bar\\"}"',
     },
     'throws an error if `result` is not found',
   );