diff --git a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
index d40c514..6c7ab72 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
@@ -222,7 +222,7 @@ public class ModelConstants {
 	public static final Qualifier ALTERNATIVE_TITLE_QUALIFIER = qualifier(
 			"alternative title", "alternative title", DNET_DATACITE_TITLE);
 
-	private static final Qualifier SUBTITLE_QUALIFIER = qualifier("subtitle", "subtitle", DNET_DATACITE_TITLE);
+	public static final Qualifier SUBTITLE_QUALIFIER = qualifier("subtitle", "subtitle", DNET_DATACITE_TITLE);
 
 	public static final AccessRight OPEN_ACCESS_RIGHT() {