diff --git a/test/test_kafka_rest_client.js b/test/test_kafka_rest_client.js
index 361529a..072b86b 100644
--- a/test/test_kafka_rest_client.js
+++ b/test/test_kafka_rest_client.js
@@ -240,7 +240,7 @@ function verifyHeader(assert, PORT, restClient) {
     restClient.urlToHttpClientMapping[urlPath] = mockedHttpClient;
     restClient.produce(getProduceMessage(topicName, 'bla', timeStamp, 'binary'),
         function assertErrorThrows(err) {
-            assert.true(err !== null);
+            assert.true(err !== null && err !== undefined);
         });
     assert.true(mockedHttpClient.postMethodCalled);
 }