diff --git a/source/mijin/async/coroutine_sleep.hpp b/source/mijin/async/coroutine_sleep.hpp
index 829e9e7..bda029d 100644
--- a/source/mijin/async/coroutine_sleep.hpp
+++ b/source/mijin/async/coroutine_sleep.hpp
@@ -13,12 +13,12 @@ namespace mijin
 template<typename Rep, typename Period>
 Task<> c_sleep(std::chrono::duration<Rep, Period> duration)
 {
-    auto now = std::chrono::high_resolution_clock::now();
+    auto now = std::chrono::steady_clock::now();
     const auto end = now + duration;
     while (now < end)
     {
         co_await c_suspend();
-        now = std::chrono::high_resolution_clock::now();
+        now = std::chrono::steady_clock::now();
     }
     co_return;
 }