diff --git a/packages/marshal/test/test-marshal-smallcaps-builder.js b/packages/marshal/test/test-marshal-smallcaps-builder.js
index 6d44ee0fc2..336250072a 100644
--- a/packages/marshal/test/test-marshal-smallcaps-builder.js
+++ b/packages/marshal/test/test-marshal-smallcaps-builder.js
@@ -351,7 +351,7 @@ test('smallcaps encoding examples', t => {
   harden(nonPassableErr);
   t.throws(() => passStyleOf(nonPassableErr), {
     message:
-      /Passed Error has extra unpassed properties {"extraProperty":{"value":"something bad","writable":.*,"enumerable":true,"configurable":.*}}/,
+      'Passed Error has extra unpassed properties {"extraProperty":{"configurable":false,"enumerable":true,"value":"something bad","writable":false}}',
   });
   assertSer(
     nonPassableErr,
diff --git a/packages/marshal/test/test-marshal-smallcaps.js b/packages/marshal/test/test-marshal-smallcaps.js
index e150fc483a..85abddde0e 100644
--- a/packages/marshal/test/test-marshal-smallcaps.js
+++ b/packages/marshal/test/test-marshal-smallcaps.js
@@ -351,7 +351,7 @@ test('smallcaps encoding examples', t => {
   harden(nonPassableErr);
   t.throws(() => passStyleOf(nonPassableErr), {
     message:
-      /Passed Error has extra unpassed properties {"extraProperty":{"configurable":.*,"enumerable":true,"value":"something bad","writable":.*}}/,
+      'Passed Error has extra unpassed properties {"extraProperty":{"configurable":false,"enumerable":true,"value":"something bad","writable":false}}',
   });
   assertSer(
     nonPassableErr,