diff --git a/lib/delayed/job_groups/railtie.rb b/lib/delayed/job_groups/railtie.rb
new file mode 100644
index 0000000..7a7a210
--- /dev/null
+++ b/lib/delayed/job_groups/railtie.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Delayed
+  module JobGroups
+    class Railtie < ::Rails::Railtie
+      config.after_initialize do
+        Delayed::Backend::ActiveRecord::Job.include(Delayed::JobGroups::JobExtensions)
+      end
+    end
+  end
+end
diff --git a/lib/delayed_job_groups_plugin.rb b/lib/delayed_job_groups_plugin.rb
index 7d6bcc1..1c69651 100644
--- a/lib/delayed_job_groups_plugin.rb
+++ b/lib/delayed_job_groups_plugin.rb
@@ -11,6 +11,15 @@
 require 'delayed/job_groups/yaml_loader'
 require 'delayed/job_groups/version'
 
-Delayed::Backend::ActiveRecord::Job.send(:include, Delayed::JobGroups::JobExtensions)
+if defined?(Delayed::Backend::ActiveRecord)
+  if defined?(Rails::Railtie)
+    # Postpone initialization to railtie for correct order
+    require 'delayed/job_groups/railtie'
+  else
+    # Do the same as in the railtie
+    Delayed::Backend::ActiveRecord::Job.include(Delayed::JobGroups::JobExtensions)
+  end
+end
+
 
 Delayed::Worker.plugins << Delayed::JobGroups::Plugin