On routes, the match method will no longer act as a catch-all option. You should now specify which HTTP verb to respond to with the option :via
Rails 3.2
match "/users/:id" => "users#show"
Rails 4.0
match "/users/:id" => "users#show", via: :get
or specify multiple verbs
match "/users" => "users#index", via: [:get, :post]
Another option for better Rails 3.2 compatibility is to just specify your actions with explicit get, post, or any other HTTP verb. With this option, you still get your code running today and future proof it for the upgrade.
Rails 3.2 and 4.0 compatible
get "/users/:id" => "users#show"
multiple verbs
get "/users" => "users#index"
post "/users" => "users#index"