diff --git a/streams-bootstrap-core/src/main/java/com/bakdata/kafka/KafkaPropertiesFactory.java b/streams-bootstrap-core/src/main/java/com/bakdata/kafka/KafkaPropertiesFactory.java
index 7a08aea7..9973bbef 100644
--- a/streams-bootstrap-core/src/main/java/com/bakdata/kafka/KafkaPropertiesFactory.java
+++ b/streams-bootstrap-core/src/main/java/com/bakdata/kafka/KafkaPropertiesFactory.java
@@ -47,11 +47,11 @@ private class Task {
         private Map<String, Object> createKafkaProperties(final Map<String, Object> configOverrides) {
             this.putAll(KafkaPropertiesFactory.this.baseConfig);
             this.putAll(KafkaPropertiesFactory.this.app.createKafkaProperties());
-            final SerializationConfig serializationConfig =
-                    KafkaPropertiesFactory.this.app.defaultSerializationConfig();
             this.putAll(EnvironmentStreamsConfigParser.parseVariables(System.getenv()));
             this.putAll(KafkaPropertiesFactory.this.configuration.getKafkaConfig());
             this.putAll(KafkaPropertiesFactory.this.endpointConfig.createKafkaProperties());
+            final SerializationConfig serializationConfig =
+                    KafkaPropertiesFactory.this.app.defaultSerializationConfig();
             this.putAllValidating(serializationConfig.createProperties());
             this.putAllValidating(configOverrides);
             return Collections.unmodifiableMap(this.kafkaConfig);