diff --git a/testing-samples/testing-demo/src/test/java/org/springframework/cloud/stream/testing/processor/ToUpperCaseProcessorTests.java b/testing-samples/testing-demo/src/test/java/org/springframework/cloud/stream/testing/processor/ToUpperCaseProcessorTests.java
index 3daa4d4..7c80815 100644
--- a/testing-samples/testing-demo/src/test/java/org/springframework/cloud/stream/testing/processor/ToUpperCaseProcessorTests.java
+++ b/testing-samples/testing-demo/src/test/java/org/springframework/cloud/stream/testing/processor/ToUpperCaseProcessorTests.java
@@ -104,7 +104,7 @@ class ToUpperCaseProcessorTests {
 						.build();
 
 		Matcher<Message<Object>> sameExceptIgnorableHeaders =
-				(Matcher<Message<Object>>) (Matcher<?>) sameExceptIgnorableHeaders(expected);
+				(Matcher<Message<Object>>) (Matcher<?>) sameExceptIgnorableHeaders(expected, "accept");
 
 		assertThat(messages, receivesMessageThat(sameExceptIgnorableHeaders));
 	}