README.md in rails-settings-cached-0.3.0 vs README.md in rails-settings-cached-0.3.1

- old
+ new

@@ -14,10 +14,13 @@
 ## Setup
 
 Edit your Gemfile:
 
 ```ruby
-gem "rails-settings-cached"
+# Rails 4+
+gem "rails-settings-cached", "0.3.0"
+# Rails 3.x
+gem "rails-settings-cached", "0.2.4"
 ```
 
 Generate your settings:
 
 ```bash