diff --git a/rust-toolchain b/rust-toolchain
index a8a61591..925656db 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2022-01-01
+nightly-2022-01-19
diff --git a/user/src/bin/sleep.rs b/user/src/bin/sleep.rs
index bd1e2204..65283970 100644
--- a/user/src/bin/sleep.rs
+++ b/user/src/bin/sleep.rs
@@ -7,7 +7,7 @@ extern crate user_lib;
 use user_lib::{sleep, exit, get_time, fork, waitpid};
 
 fn sleepy() {
-    let time: usize = 1000;
+    let time: usize = 100;
     for i in 0..5 {
         sleep(time);
         println!("sleep {} x {} msecs.", i + 1, time);
@@ -27,4 +27,4 @@ pub fn main() -> i32 {
     println!("use {} msecs.", get_time() - current_time);
     println!("sleep pass.");
     0
-}
\ No newline at end of file
+}