diff --git a/dhp-workflows/dhp-aggregation/src/main/scala/eu/dnetlib/dhp/bioschema/BioschemaToOAFTransformation.scala b/dhp-workflows/dhp-aggregation/src/main/scala/eu/dnetlib/dhp/bioschema/BioschemaToOAFTransformation.scala
index c6545635d..8b8424d29 100644
--- a/dhp-workflows/dhp-aggregation/src/main/scala/eu/dnetlib/dhp/bioschema/BioschemaToOAFTransformation.scala
+++ b/dhp-workflows/dhp-aggregation/src/main/scala/eu/dnetlib/dhp/bioschema/BioschemaToOAFTransformation.scala
@@ -213,6 +213,7 @@ object BioschemaToOAFTransformation {
     val alternativeIdentifierUrl: AlternateIdentifierType = alternativeIdentifierUrls.asJava.get(0)
 
     val alternativeIdentifiers = resolvedURLPattern
+      .filter(pattern => !pattern._1.contains(datasourceKey))
       .map(pattern => {
         if (alternativeIdentifierUrl.alternateIdentifier.startsWith(s"${pattern._1}")) {
           val relatedId = StringUtils.substringAfter(alternativeIdentifierUrl.alternateIdentifier, s"${pattern._1}")
@@ -228,19 +229,10 @@ object BioschemaToOAFTransformation {
           null
       })
       .find(s => s != null)
-      .get
 
-    val defaultAlternatedIdentifer: StructuredProperty = OafMapperUtils.structuredProperty(
-      pid,
-      datasourceKey,
-      datasourceKey,
-      ModelConstants.DNET_PID_TYPES,
-      ModelConstants.DNET_PID_TYPES,
-      dataInfo
-    )
-    var finalAlternativeIdentifiers: List[StructuredProperty] = List()
-    finalAlternativeIdentifiers = List(alternativeIdentifiers) ::: List(defaultAlternatedIdentifer)
-    instance.setAlternateIdentifier(finalAlternativeIdentifiers.asJava)
+    if (alternativeIdentifiers.isDefined) {
+      instance.setAlternateIdentifier(List(alternativeIdentifiers.get).asJava)
+    }
 
     val access_rights_qualifier =
         OafMapperUtils.accessRight(