diff --git a/src/main/java/io/lettuce/core/output/IntegerListOutput.java b/src/main/java/io/lettuce/core/output/IntegerListOutput.java
index c586af56ac..5d3ac91818 100644
--- a/src/main/java/io/lettuce/core/output/IntegerListOutput.java
+++ b/src/main/java/io/lettuce/core/output/IntegerListOutput.java
@@ -31,7 +31,9 @@ public void set(long integer) {
         subscriber.onNext(output, integer);
     }
 
+    @Override
     public void set(ByteBuffer bytes) {
+        // ignore empty ByteBuffer, would fail otherwise
         if (bytes != null) {
             super.set(bytes);
         }
diff --git a/src/test/java/io/lettuce/core/cluster/commands/reactive/HashClusterReactiveCommandIntegrationTests.java b/src/test/java/io/lettuce/core/cluster/commands/reactive/HashClusterReactiveCommandIntegrationTests.java
index d3ba572105..6da2e608d0 100644
--- a/src/test/java/io/lettuce/core/cluster/commands/reactive/HashClusterReactiveCommandIntegrationTests.java
+++ b/src/test/java/io/lettuce/core/cluster/commands/reactive/HashClusterReactiveCommandIntegrationTests.java
@@ -1,12 +1,13 @@
 package io.lettuce.core.cluster.commands.reactive;
 
-import io.lettuce.core.cluster.api.StatefulRedisClusterConnection;
-import io.lettuce.core.commands.HashCommandIntegrationTests;
-import io.lettuce.test.ReactiveSyncInvocationHandler;
+import javax.inject.Inject;
+
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
-import javax.inject.Inject;
+import io.lettuce.core.cluster.api.StatefulRedisClusterConnection;
+import io.lettuce.core.commands.HashCommandIntegrationTests;
+import io.lettuce.test.ReactiveSyncInvocationHandler;
 
 /**
  * @author Mark Paluch
diff --git a/src/test/java/io/lettuce/core/commands/reactive/HashReactiveCommandIntegrationTests.java b/src/test/java/io/lettuce/core/commands/reactive/HashReactiveCommandIntegrationTests.java
index b5eac852de..ba8f6f6ddf 100644
--- a/src/test/java/io/lettuce/core/commands/reactive/HashReactiveCommandIntegrationTests.java
+++ b/src/test/java/io/lettuce/core/commands/reactive/HashReactiveCommandIntegrationTests.java
@@ -1,18 +1,20 @@
 package io.lettuce.core.commands.reactive;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.stream.Collectors;
+
+import javax.inject.Inject;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+import reactor.test.StepVerifier;
 import io.lettuce.core.KeyValue;
 import io.lettuce.core.Value;
 import io.lettuce.core.api.StatefulRedisConnection;
 import io.lettuce.core.commands.HashCommandIntegrationTests;
 import io.lettuce.test.ReactiveSyncInvocationHandler;
-import org.junit.jupiter.api.Disabled;
-import org.junit.jupiter.api.Test;
-import reactor.test.StepVerifier;
-
-import javax.inject.Inject;
-import java.util.stream.Collectors;
-
-import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * x