diff --git a/lib/deprecation_toolkit.rb b/lib/deprecation_toolkit.rb
index 13b9317..407394a 100644
--- a/lib/deprecation_toolkit.rb
+++ b/lib/deprecation_toolkit.rb
@@ -18,20 +18,35 @@ module Behaviors
     autoload :CIRecordHelper,          "deprecation_toolkit/behaviors/ci_record_helper"
   end
 
-  def self.add_notify_behavior
-    notify = ActiveSupport::Deprecation::DEFAULT_BEHAVIORS[:notify]
-    behaviors = ActiveSupport::Deprecation.behavior
+  class << self
+    def add_notify_behavior
+      notify = ActiveSupport::Deprecation::DEFAULT_BEHAVIORS[:notify]
 
-    unless behaviors.find { |behavior| behavior == notify }
-      ActiveSupport::Deprecation.behavior = behaviors << notify
+      each_deprecator do |deprecator|
+        behaviors = deprecator.behavior
+
+        unless behaviors.find { |behavior| behavior == notify }
+          deprecator.behavior = (behaviors << notify)
+        end
+      end
+    end
+
+    def attach_subscriber
+      return if DeprecationSubscriber.already_attached?
+
+      Configuration.attach_to.each do |gem_name|
+        DeprecationSubscriber.attach_to(gem_name)
+      end
     end
-  end
 
-  def self.attach_subscriber
-    return if DeprecationSubscriber.already_attached?
+    private
 
-    Configuration.attach_to.each do |gem_name|
-      DeprecationSubscriber.attach_to(gem_name)
+    def each_deprecator(&block)
+      if defined?(Rails.application) && Rails.application.respond_to?(:deprecators)
+        Rails.application.deprecators.each(&block)
+      else
+        block.call(ActiveSupport::Deprecation)
+      end
     end
   end
 end
diff --git a/lib/minitest/deprecation_toolkit_plugin.rb b/lib/minitest/deprecation_toolkit_plugin.rb
index e888c90..d899ec3 100644
--- a/lib/minitest/deprecation_toolkit_plugin.rb
+++ b/lib/minitest/deprecation_toolkit_plugin.rb
@@ -13,6 +13,7 @@ def plugin_deprecation_toolkit_init(options)
     return unless using_bundler?
 
     require "deprecation_toolkit"
+
     if options[:record_deprecations]
       DeprecationToolkit::Configuration.behavior = DeprecationToolkit::Behaviors::Record
     end
diff --git a/test/minitest/deprecation_toolkit_plugin_test.rb b/test/minitest/deprecation_toolkit_plugin_test.rb
index 73ef589..94d38d0 100644
--- a/test/minitest/deprecation_toolkit_plugin_test.rb
+++ b/test/minitest/deprecation_toolkit_plugin_test.rb
@@ -5,6 +5,31 @@
 
 module Minitest
   class DeprecationToolkitPluginTest < ActiveSupport::TestCase
+    class FakeApplication
+      class Deprecator
+        def behavior
+          @behavior ||= []
+        end
+
+        attr_writer :behavior
+      end
+
+      class Deprecatiors < Array
+        def initialize(number)
+          super()
+          number.times { self << Deprecator.new }
+        end
+
+        def behaviour=(value)
+          each { |deprecator| deprecator.behaviour = value }
+        end
+      end
+
+      def deprecators
+        @deprecators ||= Deprecatiors.new(3)
+      end
+    end
+
     test ".plugin_deprecation_toolkit_options when running test with the `-r` flag" do
       option_parser = OptionParser.new
       options = {}
@@ -30,6 +55,21 @@ class DeprecationToolkitPluginTest < ActiveSupport::TestCase
       assert_includes ActiveSupport::Deprecation.behavior, behavior
     end
 
+    test ".plugin_deprecation_toolkit_init add `notify` behavior to the deprecations behavior list with Rails.application.deprecators" do
+      behavior = ActiveSupport::Deprecation::DEFAULT_BEHAVIORS[:notify]
+
+      Rails.singleton_class.define_method(:application) { @application ||= FakeApplication.new }
+
+      Minitest.plugin_deprecation_toolkit_init({})
+
+      Rails.application.deprecators.each do |deprecator|
+        assert_includes(deprecator.behavior, behavior)
+      end
+
+    ensure
+      Rails.singleton_class.undef_method(:application)
+    end
+
     test ".plugin_deprecation_toolkit_init doesn't remove previous deprecation behaviors" do
       behavior = ActiveSupport::Deprecation::DEFAULT_BEHAVIORS[:silence]
       ActiveSupport::Deprecation.behavior = behavior
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 6b628e3..c97983a 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -8,3 +8,6 @@
 
 ActiveSupport::Deprecation.behavior = :silence
 ActiveSupport::TestCase.test_order = :random
+
+module Rails
+end