diff --git a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectInputWithMapper.java b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectInputWithMapper.java
index 987f136..61ca33a 100644
--- a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectInputWithMapper.java
+++ b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectInputWithMapper.java
@@ -26,7 +26,7 @@ public Object readObject() throws ClassNotFoundException, IOException {
             Serializer<?> serializer = mapper.getSerializer( serializerClass )
                     .orElseThrow( () -> new IllegalArgumentException( "No serializer found for class " + serializerClass ) );
 
-            value = serializer.read(in);
+            value = serializer.read(this);
         }
         return value;
     }
diff --git a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectOutputWithMapper.java b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectOutputWithMapper.java
index 95ca12d..5ea7575 100644
--- a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectOutputWithMapper.java
+++ b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectOutputWithMapper.java
@@ -1,12 +1,14 @@
 package org.bsc.langgraph4j.serializer.std;
 
 import lombok.NonNull;
+import lombok.extern.slf4j.Slf4j;
 import org.bsc.langgraph4j.serializer.Serializer;
 
 import java.io.IOException;
 import java.io.ObjectOutput;
 import java.util.Optional;
 
+@Slf4j
 class ObjectOutputWithMapper implements ObjectOutput {
 
     private final ObjectOutput out;
@@ -19,15 +21,19 @@ public ObjectOutputWithMapper(@NonNull ObjectOutput out, @NonNull SerializerMapp
 
     @Override
     public void writeObject(Object obj) throws IOException {
+        log.trace( "{}", (obj != null) ? obj.getClass() : "NULL" );
+
         Optional<Serializer<Object>> serializer = (obj != null) ?
                 mapper.getSerializer(obj.getClass()) :
                 Optional.empty();
         // check if written by serializer
         if (serializer.isPresent()) {
+            log.trace( "use serializer {}", serializer.get().getClass().getSimpleName() );
             out.writeObject(obj.getClass());
-            serializer.get().write(obj, out);
+            serializer.get().write(obj, this);
         }
         else {
+            log.trace( "no serializer found!" );
             out.writeObject(obj);
         }
         out.flush();
diff --git a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectStreamStateSerializer.java b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectStreamStateSerializer.java
index 7f62d1e..9bb9bcb 100644
--- a/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectStreamStateSerializer.java
+++ b/core-jdk8/src/main/java/org/bsc/langgraph4j/serializer/std/ObjectStreamStateSerializer.java
@@ -11,7 +11,7 @@
 @Slf4j
 public class ObjectStreamStateSerializer implements Serializer<Map<String,Object>> {
 
-    static class ListSerializer extends BaseSerializer<List<Object>> {
+    static class ListSerializer implements Serializer<List<Object>> {
 
         @Override
         public void write(List<Object> object, ObjectOutput out) throws IOException {