diff --git a/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/CleaningFunctions.java b/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/CleaningFunctions.java
index d759114..1d12478 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/CleaningFunctions.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/CleaningFunctions.java
@@ -22,7 +22,7 @@ public class CleaningFunctions {
 		PID_BLACKLIST.add("na");
 	}
 
-	private CleaningFunctions() {}
+	public CleaningFunctions() {}
 
 	/**
 	 * Utility method that filter PID values on a per-type basis.