diff --git a/README.md b/README.md
index 15924d29..33ec92c7 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,7 @@ This project uses system (libc) memory allocator (Rust's default). But it also a
 Install from [crates.io](https://crates.io/crates/shadowsocks-rust):
 
 ```bash
+rustup default nightly-2021-05-21
 cargo install shadowsocks-rust
 ```