diff --git a/src/main/java/org/gcube/informationsystem/types/impl/entities/ResourceTypeDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/entities/ResourceTypeDefinitionImpl.java
index afcc749..5e6a553 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/entities/ResourceTypeDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/entities/ResourceTypeDefinitionImpl.java
@@ -28,6 +28,10 @@ public class ResourceTypeDefinitionImpl extends EntityTypeDefinitionImpl impleme
 	protected List<ResourceEntryDefinition> facets;
 	protected List<ResourceEntryDefinition> resources;
 	
+	protected ResourceTypeDefinitionImpl() {
+		super();
+	}
+	
 	public ResourceTypeDefinitionImpl(Class<? extends Resource> clz) {
 		super(clz);
 		setResourceSchemaEntries(clz);