diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/GroupEntitiesSparkJob.java b/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/GroupEntitiesSparkJob.java
index 98ec09277..5ce203241 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/GroupEntitiesSparkJob.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/GroupEntitiesSparkJob.java
@@ -85,8 +85,6 @@ public class GroupEntitiesSparkJob {
 		log.info("filterInvisible: {}", filterInvisible);
 
 		SparkConf conf = new SparkConf();
-		conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
-		conf.registerKryoClasses(ModelSupport.getOafModelClasses());
 
 		final VocabularyGroup vocs = VocabularyGroup.loadVocsFromIS(isLookUpService);