diff --git a/README.md b/README.md
index f2df9c2e..ccefc9a7 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ struct person
     std::string  name;
     int          age;
 };
-#if __cplusplus >= 202002L
+#if __cplusplus < 202002L
 YLT_REFL(person, name, age) //define meta data
 #endif
 ```