diff --git a/engine.go b/engine.go
index ba248cf0..18c8d656 100644
--- a/engine.go
+++ b/engine.go
@@ -967,23 +967,18 @@ func (engine *Engine) mapType(v reflect.Value) *core.Table {
 					continue
 				}
 				if strings.ToUpper(tags[0]) == "EXTENDS" {
-					if fieldValue.Kind() == reflect.Struct {
-						parentTable := engine.mapType(fieldValue)
-						for _, col := range parentTable.Columns() {
-							col.FieldName = fmt.Sprintf("%v.%v", t.Field(i).Name, col.FieldName)
-							table.AddColumn(col)
-						}
-
-						continue
-					} else if fieldValue.Kind() == reflect.Ptr {
+					switch fieldValue.Kind() {
+					case reflect.Ptr:
 						f := fieldValue.Type().Elem()
 						if f.Kind() == reflect.Struct {
+							fieldPtr := fieldValue
 							fieldValue = fieldValue.Elem()
-							if !fieldValue.IsValid() || fieldValue.IsNil() {
+							if !fieldValue.IsValid() || fieldPtr.IsNil() {
 								fieldValue = reflect.New(f).Elem()
 							}
 						}
-
+						fallthrough
+					case reflect.Struct:
 						parentTable := engine.mapType(fieldValue)
 						for _, col := range parentTable.Columns() {
 							col.FieldName = fmt.Sprintf("%v.%v", t.Field(i).Name, col.FieldName)
@@ -991,8 +986,9 @@ func (engine *Engine) mapType(v reflect.Value) *core.Table {
 						}
 
 						continue
+					default:
+						//TODO: warning
 					}
-					//TODO: warning
 				}
 
 				indexNames := make(map[string]int)