diff --git a/actionpack/lib/action_dispatch/testing/test_process.rb b/actionpack/lib/action_dispatch/testing/test_process.rb
index 69e7cdc8e7..35d2e98eef 100644
--- a/actionpack/lib/action_dispatch/testing/test_process.rb
+++ b/actionpack/lib/action_dispatch/testing/test_process.rb
@@ -6,14 +6,16 @@ require "action_dispatch/middleware/flash"
 module ActionDispatch
   module TestProcess
     module FixtureFile
-      # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.fixture_path, path), type)</tt>:
+      # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.file_fixture_path, path), type)</tt>:
       #
-      #   post :change_avatar, params: { avatar: fixture_file_upload('files/spongebob.png', 'image/png') }
+      #   post :change_avatar, params: { avatar: fixture_file_upload('spongebob.png', 'image/png') }
+      #
+      # Default fixture files location is <tt>test/fixtures/files</tt>.
       #
       # To upload binary files on Windows, pass <tt>:binary</tt> as the last parameter.
       # This will not affect other platforms:
       #
-      #   post :change_avatar, params: { avatar: fixture_file_upload('files/spongebob.png', 'image/png', :binary) }
+      #   post :change_avatar, params: { avatar: fixture_file_upload('spongebob.png', 'image/png', :binary) }
       def fixture_file_upload(path, mime_type = nil, binary = false)
         if self.class.respond_to?(:fixture_path) && self.class.fixture_path &&
             !File.exist?(path)
@@ -33,7 +35,7 @@ module ActionDispatch
               In Rails 6.2, the path needs to be relative to `file_fixture_path`.
 
               Please modify the call from
-              `fixture_file_upload(#{original_path})` to `fixture_file_upload(#{non_deprecated_path})`.
+              `fixture_file_upload("#{original_path}")` to `fixture_file_upload("#{non_deprecated_path}")`.
             EOM
           else
             path = file_fixture(original_path)
diff --git a/actionpack/test/controller/test_case_test.rb b/actionpack/test/controller/test_case_test.rb
index d21a3ae829..36a1d550a3 100644
--- a/actionpack/test/controller/test_case_test.rb
+++ b/actionpack/test/controller/test_case_test.rb
@@ -874,7 +874,7 @@ XML
 
   def test_fixture_path_is_accessed_from_self_instead_of_active_support_test_case
     TestCaseTest.stub :fixture_path, File.expand_path("../fixtures", __dir__) do
-      expected = "`fixture_file_upload(multipart/ruby_on_rails.jpg)` to `fixture_file_upload(ruby_on_rails.jpg)`"
+      expected = "`fixture_file_upload(\"multipart/ruby_on_rails.jpg\")` to `fixture_file_upload(\"ruby_on_rails.jpg\")`"
 
       assert_deprecated(expected) do
         uploaded_file = fixture_file_upload("multipart/ruby_on_rails.jpg", "image/png")
@@ -940,7 +940,7 @@ XML
 
   def test_fixture_file_upload_relative_to_fixture_path
     TestCaseTest.stub :fixture_path, File.expand_path("../fixtures", __dir__) do
-      expected = "`fixture_file_upload(multipart/ruby_on_rails.jpg)` to `fixture_file_upload(ruby_on_rails.jpg)`"
+      expected = "`fixture_file_upload(\"multipart/ruby_on_rails.jpg\")` to `fixture_file_upload(\"ruby_on_rails.jpg\")`"
 
       assert_deprecated(expected) do
         uploaded_file = fixture_file_upload("multipart/ruby_on_rails.jpg", "image/jpg")