diff --git a/Gemfile b/Gemfile
index e58f0a1c8..0c1166295 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem  'rake'
+gem 'rake'
 
 platforms :ruby do
   gem 'sqlite3'
@@ -12,11 +12,11 @@ platforms :jruby do
 end
 
 group :test do
-  gem 'activerecord', '>= 3.0'
-  gem 'actionmailer', '>= 3.0'
+  gem 'activerecord', ['>= 3.0', '< 4.1']
+  gem 'actionmailer', ['>= 3.0', '< 4.1']
+  gem 'coveralls', :require => false
   gem 'rspec', '>= 2.11'
   gem 'simplecov', :require => false
-  gem 'coveralls', :require => false
 end
 
 gemspec
diff --git a/contrib/delayed_job_multiple.monitrc b/contrib/delayed_job_multiple.monitrc
index 492bbf23f..2f63e72f8 100644
--- a/contrib/delayed_job_multiple.monitrc
+++ b/contrib/delayed_job_multiple.monitrc
@@ -4,7 +4,7 @@
 # 1. copy to /var/www/apps/{app_name}/shared/delayed_job.monitrc
 # 2. replace {app_name} as appropriate
 #    you might also need to change the program strings to
-#           "/bin/su - {username} -c '/usr/bin/env ...'" 
+#           "/bin/su - {username} -c '/usr/bin/env ...'"
 #    to load your shell environment.
 #
 # 3. add this to your /etc/monit/monitrc
diff --git a/delayed_job.gemspec b/delayed_job.gemspec
index 4b7360025..4c986a81d 100644
--- a/delayed_job.gemspec
+++ b/delayed_job.gemspec
@@ -1,7 +1,7 @@
 # -*- encoding: utf-8 -*-
 
 Gem::Specification.new do |spec|
-  spec.add_dependency   'activesupport', '>= 3.0'
+  spec.add_dependency   'activesupport', ['>= 3.0', '< 4.1']
   spec.authors        = ["Brandon Keepers", "Brian Ryckbost", "Chris Gaffney", "David Genord II", "Erik Michaels-Ober", "Matt Griffin", "Steve Richert", "Tobias Lütke"]
   spec.description    = "Delayed_job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is a direct extraction from Shopify where the job table is responsible for a multitude of core tasks."
   spec.email          = ['brian@collectiveidea.com']
diff --git a/lib/delayed/message_sending.rb b/lib/delayed/message_sending.rb
index ee9f969c6..7610d6cbc 100644
--- a/lib/delayed/message_sending.rb
+++ b/lib/delayed/message_sending.rb
@@ -9,7 +9,7 @@
 module Delayed
   if ActiveSupport::VERSION::MAJOR == 4
     klass = ActiveSupport::ProxyObject
-  else 
+  else
     klass = ActiveSupport::BasicObject
   end
 
diff --git a/lib/delayed/recipes.rb b/lib/delayed/recipes.rb
index 53d394333..18f8a162e 100644
--- a/lib/delayed/recipes.rb
+++ b/lib/delayed/recipes.rb
@@ -31,7 +31,7 @@ def args
     def roles
       fetch(:delayed_job_server_role, :app)
     end
-    
+
     def delayed_job_command
       fetch(:delayed_job_command, "script/delayed_job")
     end