diff --git a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/FAIR_Data_GuidelinesProfile.java b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/FAIR_Data_GuidelinesProfile.java
index 10e8bfe..fe2de34 100644
--- a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/FAIR_Data_GuidelinesProfile.java
+++ b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/FAIR_Data_GuidelinesProfile.java
@@ -162,14 +162,14 @@ public final class FAIR_Data_GuidelinesProfile extends AbstractOpenAireProfile {
 
     //    globally unique identifier
     private static final ElementSpec F1_01D_SPEC = Builders.
-            forMandatoryElement("identifier", ONE).
+            forMandatoryElement("identifier", ONE_TO_N).
 //            withMandatoryAttribute("identifierType", new PIDCheckValuePredicate()).
             withMandatoryAttribute("identifierType", PERSISTENT_IDENTIFIER_TYPES).
             build();
 
     //    persistent identifier
     private static final ElementSpec F1_02D_SPEC = Builders.
-            forMandatoryElement("identifier", ONE).
+            forMandatoryElement("identifier", ONE_TO_N).
             withMandatoryAttribute("identifierType", IDENTIFIER_TYPES).
             build();