diff --git a/apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/ExtSeqWithTimeWindowProducer.java b/apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/ExtSeqWithTimeWindowProducer.java
index 59bfb397ec..b4b890ffe7 100644
--- a/apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/ExtSeqWithTimeWindowProducer.java
+++ b/apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/ExtSeqWithTimeWindowProducer.java
@@ -12,7 +12,7 @@ public class ExtSeqWithTimeWindowProducer {
     public static void main(String[] args) {
         Properties props = new Properties();
         props.put("bootstrap.servers", "localhost:9092");
-        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
+        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
         props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "com.baeldung.kafka.message.ordering.serialization.JacksonSerializer");
 
         KafkaProducer<String, Message> producer = new KafkaProducer<>(props);