diff --git a/include/ucoro/awaitable.hpp b/include/ucoro/awaitable.hpp
index 60fcf1a..49bd414 100644
--- a/include/ucoro/awaitable.hpp
+++ b/include/ucoro/awaitable.hpp
@@ -12,7 +12,6 @@
 
 #if __has_include(<coroutine>)
 #include <coroutine>
-#define UCORO_HAS_STD_COROUTINE
 #else
 #include <experimental/coroutine>
 namespace std