diff --git a/actionpack/lib/action_controller/rack_process.rb b/actionpack/lib/action_controller/rack_process.rb
index aca38bde3d..dcbcf8bc1d 100644
--- a/actionpack/lib/action_controller/rack_process.rb
+++ b/actionpack/lib/action_controller/rack_process.rb
@@ -30,7 +30,7 @@ module ActionController #:nodoc:
         SERVER_NAME SERVER_PROTOCOL
 
         HTTP_ACCEPT HTTP_ACCEPT_CHARSET HTTP_ACCEPT_ENCODING
-        HTTP_ACCEPT_LANGUAGE HTTP_CACHE_CONTROL HTTP_FROM HTTP_HOST
+        HTTP_ACCEPT_LANGUAGE HTTP_CACHE_CONTROL HTTP_FROM
         HTTP_NEGOTIATE HTTP_PRAGMA HTTP_REFERER HTTP_USER_AGENT ].each do |env|
       define_method(env.sub(/^HTTP_/n, '').downcase) do
         @env[env]