diff --git a/doc/md/schema-fields.md b/doc/md/schema-fields.md
index 71e19203f..30d98987f 100755
--- a/doc/md/schema-fields.md
+++ b/doc/md/schema-fields.md
@@ -127,7 +127,8 @@ func (Group) Fields() []ent.Field {
 // Fields of the Blob.
 func (Blob) Fields() []ent.Field {
 	return []ent.Field{
-		field.UUID("id", uuid.UUID{}),
+		field.UUID("id", uuid.UUID{}).
+			Default(uuid.New),
 	}
 }