diff --git a/src/main/java/org/gcube/portal/databook/shared/RangePosts.java b/src/main/java/org/gcube/portal/databook/shared/RangePosts.java
index 4e645b5..cd6eba2 100644
--- a/src/main/java/org/gcube/portal/databook/shared/RangePosts.java
+++ b/src/main/java/org/gcube/portal/databook/shared/RangePosts.java
@@ -11,7 +11,7 @@ import java.util.ArrayList;
 public class RangePosts implements Serializable {
 	
 	private int lastReturnedPostTimelineIndex;
-	private ArrayList<Post> posts;
+	private ArrayList<Post> posts = new ArrayList<>();
 	
 	public RangePosts() {
 		super();