diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index eab663e2e0..29d8ba3d04 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -252,7 +252,7 @@ module ActionDispatch # :nodoc:
     end
 
     # Sets the HTTP character set. In case of +nil+ parameter
-    # it sets the charset to utf-8.
+    # it sets the charset to +default_charset+.
     #
     #   response.charset = 'utf-16' # => 'utf-16'
     #   response.charset = nil      # => 'utf-8'