README.md in seo_cache-1.2.1 vs README.md in seo_cache-1.2.2

@@ -56,9 +56,11 @@
 # See options below
 
 Rails.application.config.middleware.use SeoCache::Middleware
 ```
 
+Required at least Ruby 2.6.
+
 ## Configuration
 
 Chrome path (**required**) (`disk` or `memory`):
 
 ```ruby