diff --git a/actionpack/test/controller/new_base/content_negotiation_test.rb b/actionpack/test/controller/new_base/content_negotiation_test.rb
index b98a22d..2519398 100644
--- a/actionpack/test/controller/new_base/content_negotiation_test.rb
+++ b/actionpack/test/controller/new_base/content_negotiation_test.rb
@@ -14,5 +14,10 @@ module ContentNegotiation
       get "/content_negotiation/basic/hello", {}, "HTTP_ACCEPT" => "*/*"
       assert_body "Hello world */*!"
     end
+
+    test "An empty accept header will return HTML" do
+      get "/content_negotiation/basic/hello", {}, "HTTP_ACCEPT" => nil
+      assert_body "Hello world */*!"
+    end
   end
 end