README.md in second_level_cache-2.3.3 vs README.md in second_level_cache-2.4.0

@@ -14,10 +14,16 @@
 
 ## Install
 
 In your gem file:
 
-ActiveRecord 5:
+ActiveRecord 5.2:
+
+```ruby
+gem 'second_level_cache', '~> 2.4.0'
+```
+
+ActiveRecord 5.0.x, 5.1.x:
 
 ```ruby
 gem 'second_level_cache', '~> 2.3.0'
 ```