diff --git a/.travis.yml b/.travis.yml
index 76f1746..6557880 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,7 @@ gemfile:
   - gemfiles/Gemfile-rails.4.0.x
   - gemfiles/Gemfile-rails.4.1.x
   - gemfiles/Gemfile-rails.4.2.x
+  - gemfiles/Gemfile-rails.5.0.x
   - Gemfile
 matrix:
  exclude:
@@ -22,6 +23,12 @@ matrix:
      gemfile: gemfiles/Gemfile-rails.3.2.x
    - rvm: 2.4.1
      gemfile: gemfiles/Gemfile-rails.3.2.x
+   - rvm: 1.9.3
+     gemfile: gemfiles/Gemfile-rails.5.0.x
+   - rvm: 2.0.0
+     gemfile: gemfiles/Gemfile-rails.5.0.x
+   - rvm: 2.1.5
+     gemfile: gemfiles/Gemfile-rails.5.0.x
    - rvm: 1.9.3
      gemfile: Gemfile
    - rvm: 2.0.0
diff --git a/Gemfile b/Gemfile
index 34542c5..6ef3dcf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,5 +6,5 @@ gem 'rake'
 # https://github.com/rdoc/rdoc/blob/e02728fdf440012ace74b62b00b4f4954d2f91c3/History.rdoc#430--2016-11-04
 gem 'rdoc', ">= 4.3"
 
-gem 'actionmailer', '~> 5.0.0'
-gem 'activemodel', '~> 5.0.0'
+gem 'actionmailer', '~> 5.1.0'
+gem 'activemodel', '~> 5.1.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 9cb081a..2cf6009 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,80 +2,78 @@ PATH
   remote: .
   specs:
     mail_form (1.6.0)
-      actionmailer (>= 3.2, < 5.1)
-      activemodel (>= 3.2, < 5.1)
+      actionmailer (>= 3.2, < 5.2)
+      activemodel (>= 3.2, < 5.2)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (5.0.0)
-      actionpack (= 5.0.0)
-      actionview (= 5.0.0)
-      activejob (= 5.0.0)
+    actionmailer (5.1.0)
+      actionpack (= 5.1.0)
+      actionview (= 5.1.0)
+      activejob (= 5.1.0)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 2.0)
-    actionpack (5.0.0)
-      actionview (= 5.0.0)
-      activesupport (= 5.0.0)
+    actionpack (5.1.0)
+      actionview (= 5.1.0)
+      activesupport (= 5.1.0)
       rack (~> 2.0)
       rack-test (~> 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.0.0)
-      activesupport (= 5.0.0)
+    actionview (5.1.0)
+      activesupport (= 5.1.0)
       builder (~> 3.1)
-      erubis (~> 2.7.0)
+      erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    activejob (5.0.0)
-      activesupport (= 5.0.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.1.0)
+      activesupport (= 5.1.0)
       globalid (>= 0.3.6)
-    activemodel (5.0.0)
-      activesupport (= 5.0.0)
-    activesupport (5.0.0)
+    activemodel (5.1.0)
+      activesupport (= 5.1.0)
+    activesupport (5.1.0)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     builder (3.2.2)
-    concurrent-ruby (1.0.2)
-    erubis (2.7.0)
-    globalid (0.3.6)
-      activesupport (>= 4.1.0)
-    i18n (0.7.0)
+    concurrent-ruby (1.0.5)
+    erubi (1.6.0)
+    globalid (0.4.0)
+      activesupport (>= 4.2.0)
+    i18n (0.8.1)
     loofah (2.0.3)
       nokogiri (>= 1.5.9)
-    mail (2.6.4)
+    mail (2.6.5)
       mime-types (>= 1.16, < 4)
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     mini_portile2 (2.1.0)
-    minitest (5.9.0)
-    nokogiri (1.6.8)
+    minitest (5.10.1)
+    nokogiri (1.7.1)
       mini_portile2 (~> 2.1.0)
-      pkg-config (~> 1.1.7)
-    pkg-config (1.1.7)
     rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)
-    rails-dom-testing (2.0.1)
+    rails-dom-testing (2.0.2)
       activesupport (>= 4.2.0, < 6.0)
-      nokogiri (~> 1.6.0)
+      nokogiri (~> 1.6)
     rails-html-sanitizer (1.0.3)
       loofah (~> 2.0)
     rake (11.2.2)
     rdoc (5.1.0)
-    thread_safe (0.3.5)
-    tzinfo (1.2.2)
+    thread_safe (0.3.6)
+    tzinfo (1.2.3)
       thread_safe (~> 0.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  actionmailer (~> 5.0.0)
-  activemodel (~> 5.0.0)
+  actionmailer (~> 5.1.0)
+  activemodel (~> 5.1.0)
   mail_form!
   rake
   rdoc (>= 4.3)
diff --git a/gemfiles/Gemfile-rails.5.0.x b/gemfiles/Gemfile-rails.5.0.x
new file mode 100644
index 0000000..614bcd1
--- /dev/null
+++ b/gemfiles/Gemfile-rails.5.0.x
@@ -0,0 +1,9 @@
+source 'https://rubygems.org'
+
+gemspec path: '..'
+
+gem 'rake'
+gem 'rdoc'
+
+gem 'actionmailer', '~> 5.0.0'
+gem 'activemodel', '~> 5.0.0'
diff --git a/mail_form.gemspec b/mail_form.gemspec
index e51f401..d213425 100644
--- a/mail_form.gemspec
+++ b/mail_form.gemspec
@@ -12,13 +12,13 @@ Gem::Specification.new do |s|
   s.description = "Send e-mail straight from forms in Rails with I18n, validations, attachments and request information."
   s.authors     = ['José Valim', 'Carlos Antônio']
   s.license     = 'MIT'
-  
+
   s.files         = Dir["CHANGELOG", "MIT-LICENSE", "README.md", "lib/**/*"]
   s.test_files    = Dir["test/**/*"]
   s.require_paths = ["lib"]
 
   s.rubyforge_project = "mail_form"
 
-  s.add_dependency('actionmailer', '>= 3.2', '< 5.1')
-  s.add_dependency('activemodel', '>= 3.2', '< 5.1')
+  s.add_dependency('actionmailer', '>= 3.2', '< 5.2')
+  s.add_dependency('activemodel', '>= 3.2', '< 5.2')
 end