README.md in yao-0.3.8 vs README.md in yao-0.4.0

- old
+ new

@@ -60,10 +60,10 @@
 
 ## Support policy
 
 YAO supports rubies which are supported by Ruby Core Team. Please look into [`.travis.yml`](./.travis.yml) 's directive.
 
-If you want to use YAO's full functionality, e.g Ruby 2.0 or below, please create an issue or a PR first (PR Recommended ;) ).
+If you want to use YAO's full functionality, e.g Ruby 2.3 or below, please create an issue or a PR first (PR Recommended ;) ).
 
 ## Pro tips
 
 You can use a prittier namespace: