diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0515461..9601f3e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,7 +9,7 @@ jobs:
   test:
     strategy:
       matrix:
-        ruby: [ '3.3', '3.2', '3.1', '3.0', '2.7', '2.6', '2.5' ]
+        ruby: [ '4.0', '3.4', '3.3', '3.2', '3.1', '3.0', '2.7' ]
       fail-fast: false
     runs-on: ubuntu-latest
     name: ${{ matrix.ruby }}
diff --git a/decorators.gemspec b/decorators.gemspec
index cf4d34d..518e1a8 100644
--- a/decorators.gemspec
+++ b/decorators.gemspec
@@ -18,8 +18,8 @@ Gem::Specification.new do |s|
     readme.md
   ]
 
-  s.add_dependency "railties", ">= 4.0.0", "< 7.2"
-  s.add_development_dependency "rspec", "~> 3.5", ">= 3.5.0"
+  s.add_dependency "railties", ">= 4.0.0", "< 9"
+  s.add_development_dependency "rspec", ">= 3.5.0"
 
   s.cert_chain = ["certs/parndt.pem"]
   if $0.end_with?("gem") && ARGV.include?("build") && ARGV.include?(__FILE__)
diff --git a/lib/decorators.rb b/lib/decorators.rb
index 29a9916..f139221 100644
--- a/lib/decorators.rb
+++ b/lib/decorators.rb
@@ -1,6 +1,9 @@
-module Decorators
-  require "decorators/paths"
+# frozen_string_literal: true
+
+require "decorators/paths"
+require "decorators/railtie"
 
+module Decorators
   class << self
     def load!(cache_classes)
       decorators_with_argument_errors = []
@@ -22,9 +25,20 @@ def decorators
     def register!(*paths_to_register)
       paths_to_register.flatten.map do |path|
         paths.register! path
+        ignore_decorators_path(path)
       end
     end
 
+    # Tell Zeitwerk to ignore decorator paths (they're loaded manually)
+    def ignore_decorators_path(path)
+      return unless defined?(Rails.autoloaders) && Rails.autoloaders.main
+
+      decorators_path = path.join("app", "decorators")
+      Rails.autoloaders.main.ignore(decorators_path) if decorators_path.exist?
+    rescue StandardError
+      # Silently ignore if autoloaders aren't ready yet
+    end
+
     private
 
     def paths
@@ -52,5 +66,3 @@ def pattern
     end
   end
 end
-
-require "decorators/railtie"
diff --git a/lib/decorators/paths.rb b/lib/decorators/paths.rb
index b906f88..e5fd3c3 100644
--- a/lib/decorators/paths.rb
+++ b/lib/decorators/paths.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "pathname"
 
 module Decorators
diff --git a/lib/decorators/railtie.rb b/lib/decorators/railtie.rb
index 0cb402a..6820ca2 100644
--- a/lib/decorators/railtie.rb
+++ b/lib/decorators/railtie.rb
@@ -1,8 +1,14 @@
+# frozen_string_literal: true
+
 require "rails"
 
 module Decorators
   class Railtie < Rails::Railtie
     config.before_initialize do |app|
+      # Tell Zeitwerk to ignore app/decorators in the main app
+      app_decorators = Rails.root.join("app", "decorators")
+      Rails.autoloaders.main.ignore(app_decorators) if app_decorators.exist?
+
       loader = proc { Decorators.load!(app.config.cache_classes) }
 
       if app.config.eager_load