diff --git a/models/issue.go b/models/issue.go
index dffd5a8aaa..2bc25da447 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -1619,7 +1619,7 @@ func DeleteMilestoneByID(mid int64) error {
 		return err
 	}
 
-	if _, err = sess.Id(m.ID).Delete(m); err != nil {
+	if _, err = sess.Id(m.ID).Delete(new(Milestone)); err != nil {
 		return err
 	}