diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index 79a2ef965bf66c5d19efefb97ae6728ca6210298..7c585dbe680798399553c338d0e4a09095ad23ed 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -85,7 +85,7 @@ def path_parameters
 
         def set_binary_encoding(params)
           action = params[:action]
-          if controller_class.binary_params_for?(action)
+          if binary_params_for?(action)
             ActionDispatch::Request::Utils.each_param_value(params) do |param|
               param.force_encoding ::Encoding::ASCII_8BIT
             end
@@ -93,6 +93,12 @@ def set_binary_encoding(params)
           params
         end
 
+        def binary_params_for?(action)
+          controller_class.binary_params_for?(action)
+        rescue NameError
+          false
+        end
+
         def parse_formatted_parameters(parsers)
           return yield if content_length.zero? || content_mime_type.nil?
 
diff --git a/railties/test/application/middleware/exceptions_test.rb b/railties/test/application/middleware/exceptions_test.rb
index cbb990f13bb75013d5550e253b0b1b58aea0b5fd..fe07ad3cbe1c8b20eac3561705d70a7af4bf5b44 100644
--- a/railties/test/application/middleware/exceptions_test.rb
+++ b/railties/test/application/middleware/exceptions_test.rb
@@ -100,6 +100,20 @@ def index
       end
     end
 
+    test "routing to an nonexistent controller when action_dispatch.show_exceptions and consider_all_requests_local are set shows diagnostics" do
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          resources :articles
+        end
+      RUBY
+
+      app.config.action_dispatch.show_exceptions = true
+      app.config.consider_all_requests_local = true
+
+      get "/articles"
+      assert_match "<title>Action Controller: Exception caught</title>", last_response.body
+    end
+
     test "displays diagnostics message when exception raised in template that contains UTF-8" do
       controller :foo, <<-RUBY
         class FooController < ActionController::Base