diff --git a/src/basic/compound-type/enum.md b/src/basic/compound-type/enum.md
index 31fe139b..fd1efb08 100644
--- a/src/basic/compound-type/enum.md
+++ b/src/basic/compound-type/enum.md
@@ -41,6 +41,7 @@ fn main() {
 }
 
 fn print_suit(card: PokerSuit) {
+    // 需要在定义 enum PokerSuit 的上面添加上 #[derive(Debug)]，否则会报 card 没有实现 Debug
     println!("{:?}",card);
 }
 ```