diff --git a/models/resources/resource.go b/models/resources/resource.go
index a2376b7..8bf3b19 100755
--- a/models/resources/resource.go
+++ b/models/resources/resource.go
@@ -37,7 +37,7 @@ type AbstractResource struct {
 }
 
 func (ri *AbstractResource) Extend(typ ...string) map[string][]tools.DataType {
-	dt := map[string][]tools.DataType{}
+	dt := ri.AbstractObject.Extend(typ...)
 	for _, t := range typ {
 		switch t {
 		case "purchase":