diff --git a/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java b/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
index c4e06c5..11efc85 100644
--- a/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
+++ b/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
@@ -6,8 +6,8 @@ package org.gcube.informationsystem.orientdb.hooks;
 import java.util.Calendar;
 import java.util.UUID;
 
+import org.gcube.informationsystem.base.reference.properties.Header;
 import org.gcube.informationsystem.model.reference.entities.Entity;
-import org.gcube.informationsystem.model.reference.properties.Header;
 import org.gcube.informationsystem.model.reference.relations.Relation;
 
 import com.orientechnologies.common.log.OLogManager;