diff --git a/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
index 68b5beb..2d6c26e 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
@@ -14,7 +14,6 @@ import org.gcube.informationsystem.types.TypeBinder;
 import org.gcube.informationsystem.types.annotations.ISProperty;
 import org.gcube.informationsystem.types.impl.TypeDefinitionImpl;
 import org.gcube.informationsystem.types.reference.properties.PropertyDefinition;
-import org.gcube.informationsystem.types.reference.relations.RelationTypeDefinition;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;