diff --git a/Gemfile b/Gemfile
index 19b6e268..10682fa7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -20,7 +20,7 @@ gem 'inherited_resources', '~> 1.1.2'
 gem 'rmagick', '2.12.2'
 gem 'locomotive_carrierwave', '0.5.0.1.beta3', :require => 'carrierwave'
 
-gem 'custom_fields', '1.0.0.beta.9'
+gem 'custom_fields', '1.0.0.beta.10'
 gem 'fog', '0.3.7'
 gem 'mimetype-fu'
 gem 'actionmailer-with-request', :require => 'actionmailer_with_request'
diff --git a/Gemfile.lock b/Gemfile.lock
index 518b1ab8..677e4deb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,6 +1,6 @@
 GIT
   remote: git://github.com/floehopper/mocha.git
-  revision: 2b4e868d1907859cd03f407078bd8b630f7d0dd6
+  revision: 6fe08197f214457ac122c49d96fdac8e17adbea2
   specs:
     mocha (0.9.12.20110213002255)
 
@@ -87,7 +87,7 @@ GEM
     cucumber-rails (0.3.2)
       cucumber (>= 0.8.0)
     culerity (0.2.15)
-    custom_fields (1.0.0.beta.9)
+    custom_fields (1.0.0.beta.10)
       activesupport (>= 3.0.4)
       locomotive_carrierwave
       mongoid (~> 2.0.0.rc.7)
@@ -253,7 +253,7 @@ GEM
       polyglot (>= 0.3.1)
     trollop (1.16.2)
     tzinfo (0.3.27)
-    unicorn (3.6.1)
+    unicorn (3.6.2)
       kgio (~> 2.3)
       rack
     warden (0.10.7)
@@ -276,7 +276,7 @@ DEPENDENCIES
   capybara
   cucumber (= 0.8.5)
   cucumber-rails
-  custom_fields (= 1.0.0.beta.9)
+  custom_fields (= 1.0.0.beta.10)
   database_cleaner
   delayed_job (= 2.1.4)
   delayed_job_mongoid (= 1.0.2)
diff --git a/app/views/admin/content_types/edit.html.haml b/app/views/admin/content_types/edit.html.haml
index 485a87d6..053284da 100644
--- a/app/views/admin/content_types/edit.html.haml
+++ b/app/views/admin/content_types/edit.html.haml
@@ -2,7 +2,7 @@
 
 - content_for :submenu do
   = render 'admin/shared/menu/contents'
-  
+
 - content_for :actions do
   = render 'admin/shared/actions/contents'
 
diff --git a/lib/locomotive/hosting/heroku.rb b/lib/locomotive/hosting/heroku.rb
index 5b6366e9..da00d303 100644
--- a/lib/locomotive/hosting/heroku.rb
+++ b/lib/locomotive/hosting/heroku.rb
@@ -35,6 +35,8 @@ module Locomotive
 
           self.enhance_site_model_with_heroku
 
+          self.apply_patches
+
           # "cache" domains for better performance
           self.heroku_domains = self.heroku_connection.list_domains(self.config.heroku[:name]).collect { |h| h[:domain] }
         end
@@ -51,6 +53,14 @@ module Locomotive
           Site.send :include, Locomotive::Hosting::Heroku::FirstInstallation
         end
 
+        def apply_patches
+          # for various reasons, Heroku can modify the behaviour of an application by changing the gem versions (json/pure for instance)
+          # so the purpose of this method is to correct those potential differences.
+
+          # http://blog.ethanvizitei.com/2010/11/json-pure-ruins-my-morning.html
+          Fixnum.class_eval { def to_json(options = nil); to_s; end }
+        end
+
         # manage domains
 
         def add_heroku_domain(name)
diff --git a/locomotive_cms.gemspec b/locomotive_cms.gemspec
index 74ade470..9e1ca89b 100644
--- a/locomotive_cms.gemspec
+++ b/locomotive_cms.gemspec
@@ -37,7 +37,7 @@ Gem::Specification.new do |s|
   s.add_dependency "rmagick", "2.12.2"
   s.add_dependency "locomotive_carrierwave", "0.5.0.1.beta3"
 
-  s.add_dependency "custom_fields", "1.0.0.beta.9"
+  s.add_dependency "custom_fields", "1.0.0.beta.10"
   s.add_dependency "fog", "0.3.7"
   s.add_dependency "mimetype-fu"
   s.add_dependency "actionmailer-with-request"