diff --git a/.rubocop.yml b/.rubocop.yml
index 0b022cd..7d174e5 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -3,3 +3,14 @@ Metrics/LineLength:
 
 Documentation:
   Enabled: false
+
+AllCops:
+  Include:
+    - '**/Rakefile'
+    - '**/config.ru'
+  Exclude:
+    - 'db/**/*'
+    - 'config/**/*'
+    - 'script/**/*'
+    - 'bin/**/*'
+    - !ruby/regexp /old_and_unused\.rb$/
diff --git a/app/models/photo.rb b/app/models/photo.rb
index c58a5d6..ce0b17e 100644
--- a/app/models/photo.rb
+++ b/app/models/photo.rb
@@ -5,7 +5,7 @@ class Photo < ActiveRecord::Base
 
   validates :image, presence: true
 
-  @@per_page = 11
+  self.per_page = 11
 
   scope :enabled, -> { where(enabled: true) }
 
diff --git a/config.ru b/config.ru
index 230e0be..a2dea3d 100644
--- a/config.ru
+++ b/config.ru
@@ -1,4 +1,4 @@
 # This file is used by Rack-based servers to start the application.
 
-require ::File.expand_path('../config/environment',  __FILE__)
+require ::File.expand_path('../config/environment', __FILE__)
 run DanBarberPhoto::Application
diff --git a/spec/support/ajax.rb b/spec/support/ajax.rb
index 6789773..87c0816 100644
--- a/spec/support/ajax.rb
+++ b/spec/support/ajax.rb
@@ -1,6 +1,6 @@
 module Ajax
   def wait_for_ajax
-    Timeout.timeout(Capybara.default_wait_time) do
+    Timeout.timeout(Capybara.default_max_wait_time) do
       loop do
         active = page.evaluate_script('jQuery.active')
         break if active == 0