diff --git a/src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Datasource.java b/src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Datasource.java
index 62a32a0..de845b3 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Datasource.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Datasource.java
@@ -93,7 +93,7 @@ public class Datasource implements Serializable {
 
 	private String certificates; // string
 
-	private List<Object> policies; //
+	private List<String> policies; //
 
 	private Container journal; // issn etc del Journal
 
@@ -297,11 +297,11 @@ public class Datasource implements Serializable {
 		this.certificates = certificates;
 	}
 
-	public List<Object> getPolicies() {
+	public List<String> getPolicies() {
 		return policies;
 	}
 
-	public void setPolicies(List<Object> policiesr3) {
+	public void setPolicies(List<String> policiesr3) {
 		this.policies = policiesr3;
 	}