diff --git a/railties/lib/commands/runner.rb b/railties/lib/commands/runner.rb
index c7a70a1b0baa6d957418ee99279eda33728f062f..49827c3812c9896ac4956013d79f7bb7ffbec5e6 100644
--- a/railties/lib/commands/runner.rb
+++ b/railties/lib/commands/runner.rb
@@ -20,11 +20,8 @@
   opts.parse!
 end
 
-if defined?(RAILS_ENV)
-  RAILS_ENV.replace(options[:environment])
-else
-  ENV["RAILS_ENV"] = options[:environment]
-end
+ENV["RAILS_ENV"] = options[:environment]
+RAILS_ENV.replace(options[:environment]) if defined?(RAILS_ENV)
 
 require RAILS_ROOT + '/config/environment'
 eval(ARGV.first)