diff --git a/curriculum/challenges/english/05-apis-and-microservices/apis-and-microservices-projects/timestamp-microservice.md b/curriculum/challenges/english/05-apis-and-microservices/apis-and-microservices-projects/timestamp-microservice.md
index ad70f1d3b9..00cee8bcd6 100644
--- a/curriculum/challenges/english/05-apis-and-microservices/apis-and-microservices-projects/timestamp-microservice.md
+++ b/curriculum/challenges/english/05-apis-and-microservices/apis-and-microservices-projects/timestamp-microservice.md
@@ -107,7 +107,7 @@ If the input date string is invalid, the api returns an object having the struct
       assert.equal(data.error.toLowerCase(), 'invalid date');
     },
     (xhr) => {
-      throw new Error(xhr.responseText);
+      assert(xhr.responseJSON.error.toLowerCase() === 'invalid date');
     }
   );
 ```