diff --git a/src/json.test.ts b/src/json.test.ts
index dc2706d1..817e37fa 100644
--- a/src/json.test.ts
+++ b/src/json.test.ts
@@ -40,7 +40,9 @@ describe('json', () => {
     it('returns error message', () => {
       const [error] = validate(undefined, JsonStruct);
       assert(error !== undefined);
-      expect(error.message).toStrictEqual('Expected a valid JSON-serializable value');
+      expect(error.message).toStrictEqual(
+        'Expected a valid JSON-serializable value',
+      );
     });
   });