diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/crossref/Crossref2Oaf.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/crossref/Crossref2Oaf.scala
index d1ceb9a07..9a4490579 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/crossref/Crossref2Oaf.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/crossref/Crossref2Oaf.scala
@@ -166,6 +166,9 @@ case object Crossref2Oaf {
       instance.setLicense(l.head)
 
 
+    // Ticket #6281 added pid to Instance
+    instance.setPid(result.getPid.asScala.filter(p => p.getQualifier.getClassid.equalsIgnoreCase("doi")).asJava)
+
     val has_review = (json \ "relation" \"has-review" \ "id")
 
     if(has_review != JNothing) {
diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/MagDataModel.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/MagDataModel.scala
index 7bb4686cf..41fc74000 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/MagDataModel.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/mag/MagDataModel.scala
@@ -170,6 +170,9 @@ case object ConversionUtil {
     else
       i.setUrl(List(s"https://academic.microsoft.com/#/detail/${extractMagIdentifier(pub.getOriginalId.asScala)}").asJava)
 
+    // Ticket #6281 added pid to Instance
+    i.setPid(pub.getPid.asScala.filter(p => p.getQualifier.getClassid.equalsIgnoreCase("doi")).asJava)
+
     i.setCollectedfrom(createMAGCollectedFrom())
     pub.setInstance(List(i).asJava)
     pub
diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/uw/UnpayWallToOAF.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/uw/UnpayWallToOAF.scala
index 08cd4ee8e..de1fa87e6 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/uw/UnpayWallToOAF.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/uw/UnpayWallToOAF.scala
@@ -49,6 +49,9 @@ object UnpayWallToOAF {
     i.setAccessright(getOpenAccessQualifier())
     i.setUrl(List(oaLocation.url.get).asJava)
 
+    // Ticket #6281 added pid to Instance
+    i.setPid(pub.getPid.asScala.filter(p => p.getQualifier.getClassid.equalsIgnoreCase("doi")).asJava)
+
     if (oaLocation.license.isDefined)
       i.setLicense(asField(oaLocation.license.get))
     pub.setInstance(List(i).asJava)