diff --git a/os/Cargo.toml b/os/Cargo.toml
index 8b81163..660456c 100644
--- a/os/Cargo.toml
+++ b/os/Cargo.toml
@@ -2,7 +2,7 @@
 name = "os"
 version = "0.1.0"
 authors = ["Yifan Wu <shinbokuow@163.com>"]
-edition = "2018"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html