diff --git a/src/main/java/org/gcube/informationsystem/types/PropertyTypeName.java b/src/main/java/org/gcube/informationsystem/types/PropertyTypeName.java
index fee73ef..40990a9 100644
--- a/src/main/java/org/gcube/informationsystem/types/PropertyTypeName.java
+++ b/src/main/java/org/gcube/informationsystem/types/PropertyTypeName.java
@@ -309,11 +309,13 @@ public class PropertyTypeName {
 					stringBuffer.append(BaseType.STRING.toString());
 					stringBuffer.append(",");
 				}
-				if(genericBaseType!=null) {
+				
+				if(genericClassName != null) {
 					stringBuffer.append(genericClassName);
 				}else {
 					stringBuffer.append(genericBaseType.toString());
 				}
+				
 				stringBuffer.append(">");
 				break;