diff --git a/clients/src/test/java/org/apache/kafka/clients/MockClient.java b/clients/src/test/java/org/apache/kafka/clients/MockClient.java
index 1f626435c13e4..eaf5dcb4f8fd1 100644
--- a/clients/src/test/java/org/apache/kafka/clients/MockClient.java
+++ b/clients/src/test/java/org/apache/kafka/clients/MockClient.java
@@ -44,12 +44,7 @@
  * A mock network client for use testing code
  */
 public class MockClient implements KafkaClient {
-    public static final RequestMatcher ALWAYS_TRUE = new RequestMatcher() {
-        @Override
-        public boolean matches(AbstractRequest body) {
-            return true;
-        }
-    };
+    public static final RequestMatcher ALWAYS_TRUE = body -> true;
 
     private static class FutureResponse {
         private final Node node;
diff --git a/clients/src/test/java/org/apache/kafka/clients/producer/KafkaProducerTest.java b/clients/src/test/java/org/apache/kafka/clients/producer/KafkaProducerTest.java
index 14f39a984f838..f672918eac201 100644
--- a/clients/src/test/java/org/apache/kafka/clients/producer/KafkaProducerTest.java
+++ b/clients/src/test/java/org/apache/kafka/clients/producer/KafkaProducerTest.java
@@ -767,7 +767,11 @@ public void testInitTransactionTimeout() {
 
             assertThrows(TimeoutException.class, producer::initTransactions);
 
-            client.respond(FindCoordinatorResponse.prepareResponse(Errors.NONE, host1));
+            client.prepareResponse(
+                request -> request instanceof FindCoordinatorRequest &&
+                               ((FindCoordinatorRequest) request).data().keyType() == FindCoordinatorRequest.CoordinatorType.TRANSACTION.id(),
+                FindCoordinatorResponse.prepareResponse(Errors.NONE, host1));
+
             client.prepareResponse(initProducerIdResponse(1L, (short) 5, Errors.NONE));
 
             // retry initialization should work