diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index 1acf08efe98b1749a14dc57c1809cabac38164be..297889542e77babb034b0b22f634e61e9007ee01 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -341,7 +341,7 @@ def require_environment! #:nodoc:
     end
 
     def routes_reloader #:nodoc:
-      @routes_reloader ||= RoutesReloader.new(file_watcher: config.file_watcher)
+      @routes_reloader ||= RoutesReloader.new
     end
 
     # Returns an array of file paths appended with a hash of
diff --git a/railties/lib/rails/application/routes_reloader.rb b/railties/lib/rails/application/routes_reloader.rb
index 7f86bef5afae49dcf3c5912454227ecaf3d398a3..10703622538442d20f92d72958699c4bd5661a98 100644
--- a/railties/lib/rails/application/routes_reloader.rb
+++ b/railties/lib/rails/application/routes_reloader.rb
@@ -9,11 +9,10 @@ class RoutesReloader
       attr_accessor :eager_load
       delegate :execute_if_updated, :execute, :updated?, to: :updater
 
-      def initialize(file_watcher: ActiveSupport::FileUpdateChecker)
+      def initialize
         @paths      = []
         @route_sets = []
         @eager_load = false
-        @file_watcher = file_watcher
       end
 
       def reload!
@@ -27,7 +26,7 @@ def reload!
 
     private
       def updater
-        @updater ||= @file_watcher.new(paths) { reload! }
+        @updater ||= ActiveSupport::FileUpdateChecker.new(paths) { reload! }
       end
 
       def clear!
diff --git a/railties/test/application/loading_test.rb b/railties/test/application/loading_test.rb
index 6b5357453f765582379acf79e5f194759b55099f..9ab400acfcbd944ed891b9ce28b0fd669c0bfd9e 100644
--- a/railties/test/application/loading_test.rb
+++ b/railties/test/application/loading_test.rb
@@ -184,8 +184,11 @@ def self.counter; 2; end
   test "does not reload constants on development if custom file watcher always returns false" do
     add_to_config <<-RUBY
       config.cache_classes = false
-      config.file_watcher = Class.new(ActiveSupport::FileUpdateChecker) do
+      config.file_watcher = Class.new do
+        def initialize(*); end
         def updated?; false; end
+        def execute; end
+        def execute_if_updated; false; end
       end
     RUBY