diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/SparkProcessMAG.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/SparkProcessMAG.scala
index 016279787..0ea4b66a4 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/SparkProcessMAG.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/SparkProcessMAG.scala
@@ -146,7 +146,7 @@ object SparkProcessMAG {
       .save(s"$workingPath/mag_publication")
 
     spark.read.load(s"$workingPath/mag_publication").as[Publication]
-      .filter(p => p.getId == null)
+      .filter(p => p.getId != null)
       .groupByKey(p => p.getId)
       .reduceGroups((a:Publication, b:Publication) => ConversionUtil.mergePublication(a,b))
       .map(_._2)