diff --git a/.travis.yml b/.travis.yml
index 434667c2..cfbd07b5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,12 +8,12 @@ rvm:
   - rbx
   - jruby-19mode
 gemfile:
-  - gemfiles/Gemfile.rails-head
+  - gemfiles/Gemfile.rails-4-0-stable
   - gemfiles/Gemfile.rails-4-1-stable
   - Gemfile
 matrix:
   allow_failures:
-    - gemfile: gemfiles/Gemfile.rails-head
+    - gemfile: Gemfile
     - gemfile: gemfiles/Gemfile.rails-4-1-stable
 notifications:
   email: false
diff --git a/Gemfile b/Gemfile
index c6cc84a8..798a0ec6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,9 +8,7 @@ platforms :rbx do
 end
 
 gem 'country_select', '~> 1.1.1'
-gem 'railties', github: 'rails/rails', branch: '4-0-stable'
-gem 'activemodel', github: 'rails/rails', branch: '4-0-stable'
-gem 'actionpack', github: 'rails/rails', branch: '4-0-stable'
+gem 'railties', github: 'rails/rails'
+gem 'activemodel', github: 'rails/rails'
+gem 'actionpack', github: 'rails/rails'
 gem 'rake'
-gem 'tzinfo'
-gem 'rdoc'
diff --git a/Gemfile.lock b/Gemfile.lock
index 0a4058cc..92bfe37e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,26 +1,28 @@
 GIT
   remote: git://github.com/rails/rails.git
-  revision: d682b0d4e245e321ff5f0a459e8d771c3cf73677
-  branch: 4-0-stable
+  revision: d41154094a332a3dd797c4148894fbcd1e5ad5ff
   specs:
-    actionpack (4.0.3)
-      activesupport (= 4.0.3)
-      builder (~> 3.1.0)
-      erubis (~> 2.7.0)
+    actionpack (4.2.0.alpha)
+      actionview (= 4.2.0.alpha)
+      activesupport (= 4.2.0.alpha)
       rack (~> 1.5.2)
       rack-test (~> 0.6.2)
-    activemodel (4.0.3)
-      activesupport (= 4.0.3)
-      builder (~> 3.1.0)
-    activesupport (4.0.3)
+    actionview (4.2.0.alpha)
+      activesupport (= 4.2.0.alpha)
+      builder (~> 3.1)
+      erubis (~> 2.7.0)
+    activemodel (4.2.0.alpha)
+      activesupport (= 4.2.0.alpha)
+      builder (~> 3.1)
+    activesupport (4.2.0.alpha)
       i18n (~> 0.6, >= 0.6.9)
-      minitest (~> 4.2)
-      multi_json (~> 1.3)
+      json (~> 1.7, >= 1.7.7)
+      minitest (~> 5.1)
       thread_safe (~> 0.1)
-      tzinfo (~> 0.3.37)
-    railties (4.0.3)
-      actionpack (= 4.0.3)
-      activesupport (= 4.0.3)
+      tzinfo (~> 1.1)
+    railties (4.2.0.alpha)
+      actionpack (= 4.2.0.alpha)
+      activesupport (= 4.2.0.alpha)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
 
@@ -28,32 +30,34 @@ PATH
   remote: .
   specs:
     simple_form (3.0.1)
-      actionpack (>= 4.0.0, < 4.1)
-      activemodel (>= 4.0.0, < 4.1)
+      actionpack (~> 4.0)
+      activemodel (~> 4.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    atomic (1.1.14)
-    builder (3.1.4)
+    atomic (1.1.15)
+    builder (3.2.2)
     country_select (1.1.3)
     erubis (2.7.0)
     ffi2-generators (0.1.1)
     i18n (0.6.9)
-    minitest (4.7.5)
-    multi_json (1.8.2)
+    json (1.8.1)
+    minitest (5.3.0)
     rack (1.5.2)
     rack-test (0.6.2)
       rack (>= 1.0)
     rake (10.1.1)
-    rdoc (4.1.0)
+    rubinius-compiler (2.1.0)
     rubinius-coverage (2.0.3)
-    rubinius-debugger (2.0.0)
+    rubinius-debugger (2.0.2)
+      rubinius-compiler (~> 2.0)
+      rubysl-readline (~> 2.0)
     rubinius-developer_tools (2.0.0)
       rubinius-coverage (~> 2.0)
       rubinius-debugger (~> 2.0)
       rubinius-profiler (~> 2.0)
-    rubinius-profiler (2.0.0)
+    rubinius-profiler (2.0.1)
     rubysl (2.0.15)
       rubysl-abbrev (~> 2.0)
       rubysl-base64 (~> 2.0)
@@ -212,7 +216,7 @@ GEM
     rubysl-observer (2.0.0)
     rubysl-open-uri (2.0.0)
     rubysl-open3 (2.0.0)
-    rubysl-openssl (2.0.5)
+    rubysl-openssl (2.1.0)
     rubysl-optparse (2.0.1)
       rubysl-shellwords (~> 2.0)
     rubysl-ostruct (2.0.4)
@@ -225,9 +229,9 @@ GEM
     rubysl-pty (2.0.2)
     rubysl-rational (2.0.1)
     rubysl-readline (2.0.2)
-    rubysl-resolv (2.0.0)
+    rubysl-resolv (2.1.0)
     rubysl-rexml (2.0.2)
-    rubysl-rinda (2.0.0)
+    rubysl-rinda (2.0.1)
     rubysl-rss (2.0.0)
     rubysl-scanf (2.0.0)
     rubysl-securerandom (2.0.0)
@@ -257,9 +261,10 @@ GEM
     rubysl-yaml (2.0.4)
     rubysl-zlib (2.0.1)
     thor (0.18.1)
-    thread_safe (0.1.3)
-      atomic
-    tzinfo (0.3.38)
+    thread_safe (0.2.0)
+      atomic (>= 1.1.7, < 2)
+    tzinfo (1.1.0)
+      thread_safe (~> 0.1)
 
 PLATFORMS
   ruby
@@ -270,8 +275,6 @@ DEPENDENCIES
   country_select (~> 1.1.1)
   railties!
   rake
-  rdoc
   rubinius-developer_tools
   rubysl (~> 2.0)
   simple_form!
-  tzinfo
diff --git a/gemfiles/Gemfile.rails-4-0-stable b/gemfiles/Gemfile.rails-4-0-stable
new file mode 100644
index 00000000..c3141668
--- /dev/null
+++ b/gemfiles/Gemfile.rails-4-0-stable
@@ -0,0 +1,16 @@
+source 'https://rubygems.org'
+
+gemspec path: '..'
+
+platforms :rbx do
+  gem 'rubysl', '~> 2.0'
+  gem 'rubinius-developer_tools'
+end
+
+gem 'country_select', '~> 1.1.1'
+gem 'railties', github: 'rails/rails', branch: '4-0-stable'
+gem 'activemodel', github: 'rails/rails', branch: '4-0-stable'
+gem 'actionpack', github: 'rails/rails', branch: '4-0-stable'
+gem 'rake'
+gem 'tzinfo'
+gem 'rdoc'
diff --git a/gemfiles/Gemfile.rails-head b/gemfiles/Gemfile.rails-head
deleted file mode 100644
index f479bf7d..00000000
--- a/gemfiles/Gemfile.rails-head
+++ /dev/null
@@ -1,15 +0,0 @@
-source 'https://rubygems.org'
-
-gemspec :path => '..'
-
-platforms :rbx do
-  gem 'rubysl', '~> 2.0'
-  gem 'rubinius-developer_tools'
-end
-
-gem 'country_select', '~> 1.1.1'
-gem 'railties', github: 'rails/rails'
-gem 'activemodel', github: 'rails/rails'
-gem 'actionpack', github: 'rails/rails'
-gem 'rake'
-gem 'tzinfo'
diff --git a/simple_form.gemspec b/simple_form.gemspec
index 18fab78d..3c37f661 100644
--- a/simple_form.gemspec
+++ b/simple_form.gemspec
@@ -20,6 +20,6 @@ Gem::Specification.new do |s|
 
   s.rubyforge_project = "simple_form"
 
-  s.add_dependency('activemodel', '>= 4.0.0', '< 4.1')
-  s.add_dependency('actionpack', '>= 4.0.0', '< 4.1')
+  s.add_dependency('activemodel', '~> 4.0')
+  s.add_dependency('actionpack', '~> 4.0')
 end