diff --git a/.travis.yml b/.travis.yml
index 6b3d3fe5..cfbc962f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,13 @@
+env:
+  - RUBYOPT=-W0
 rvm:
   - 2.0.0
-  - 2.1.9
-  - 2.2.7
-  - 2.3.4
+  - 2.1
+  - 2.2
+  - 2.3
+  - 2.4
+  - 2.5
+  - ruby-head
   - jruby-head
 branches:
   only: [master]
@@ -10,5 +15,6 @@ sudo: false
 cache: bundler
 matrix:
   allow_failures:
+    - rvm: ruby-head
     - rvm: jruby-head
 bundler_args: "--jobs 4"
diff --git a/appveyor.yml b/appveyor.yml
index 93a79ca0..b1eb5bde 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -6,6 +6,7 @@ environment:
     - RUBY_VERSION: 21-x64
     - RUBY_VERSION: 22-x64
     - RUBY_VERSION: 23-x64
+    - RUBY_VERSION: 24-x64
 
 install:
   - set PATH=C:\Ruby%RUBY_VERSION%\bin;%PATH%
diff --git a/spec/fixtures/rails32/Gemfile.lock b/spec/fixtures/rails32/Gemfile.lock
index 4cf42914..66b616c4 100644
--- a/spec/fixtures/rails32/Gemfile.lock
+++ b/spec/fixtures/rails32/Gemfile.lock
@@ -40,7 +40,7 @@ GEM
     hike (1.2.3)
     i18n (0.7.0)
     journey (1.0.4)
-    json (1.8.3)
+    json (1.8.6)
     mail (2.5.4)
       mime-types (~> 1.16)
       treetop (~> 1.4.8)
diff --git a/spec/fixtures/rails42/Gemfile b/spec/fixtures/rails42/Gemfile
index 0fef7861..fc84b409 100644
--- a/spec/fixtures/rails42/Gemfile
+++ b/spec/fixtures/rails42/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'rails', '4.2.2'
+gem 'rails', '4.2.8'
 gem 'sqlite3'
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw]
 gem 'parallel_tests', path: "../../../", group: :development
diff --git a/spec/fixtures/rails42/Gemfile.lock b/spec/fixtures/rails42/Gemfile.lock
index eff47a92..03302ed3 100644
--- a/spec/fixtures/rails42/Gemfile.lock
+++ b/spec/fixtures/rails42/Gemfile.lock
@@ -7,99 +7,99 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (4.2.2)
-      actionpack (= 4.2.2)
-      actionview (= 4.2.2)
-      activejob (= 4.2.2)
+    actionmailer (4.2.8)
+      actionpack (= 4.2.8)
+      actionview (= 4.2.8)
+      activejob (= 4.2.8)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 1.0, >= 1.0.5)
-    actionpack (4.2.2)
-      actionview (= 4.2.2)
-      activesupport (= 4.2.2)
+    actionpack (4.2.8)
+      actionview (= 4.2.8)
+      activesupport (= 4.2.8)
       rack (~> 1.6)
       rack-test (~> 0.6.2)
       rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.1)
-    actionview (4.2.2)
-      activesupport (= 4.2.2)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (4.2.8)
+      activesupport (= 4.2.8)
       builder (~> 3.1)
       erubis (~> 2.7.0)
       rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.1)
-    activejob (4.2.2)
-      activesupport (= 4.2.2)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (4.2.8)
+      activesupport (= 4.2.8)
       globalid (>= 0.3.0)
-    activemodel (4.2.2)
-      activesupport (= 4.2.2)
+    activemodel (4.2.8)
+      activesupport (= 4.2.8)
       builder (~> 3.1)
-    activerecord (4.2.2)
-      activemodel (= 4.2.2)
-      activesupport (= 4.2.2)
+    activerecord (4.2.8)
+      activemodel (= 4.2.8)
+      activesupport (= 4.2.8)
       arel (~> 6.0)
-    activesupport (4.2.2)
+    activesupport (4.2.8)
       i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    arel (6.0.0)
-    builder (3.2.2)
+    arel (6.0.4)
+    builder (3.2.3)
     erubis (2.7.0)
-    globalid (0.3.5)
+    globalid (0.3.7)
       activesupport (>= 4.1.0)
     i18n (0.7.0)
-    json (1.8.3)
-    loofah (2.0.2)
+    loofah (2.0.3)
       nokogiri (>= 1.5.9)
-    mail (2.6.3)
-      mime-types (>= 1.16, < 3)
-    mime-types (2.6.1)
+    mail (2.6.6)
+      mime-types (>= 1.16, < 4)
+    mime-types (2.6.2)
     mini_portile2 (2.1.0)
     minitest (5.7.0)
-    nokogiri (1.6.8.1)
+    nokogiri (1.6.8)
       mini_portile2 (~> 2.1.0)
-    nokogiri (1.6.8.1-x64-mingw32)
+      pkg-config (~> 1.1.7)
+    nokogiri (1.6.8-x64-mingw32)
       mini_portile2 (~> 2.1.0)
-    parallel (1.12.0)
-    rack (1.6.4)
+      pkg-config (~> 1.1.7)
+    parallel (1.12.1)
+    rack (1.6.8)
     rack-test (0.6.3)
       rack (>= 1.0)
-    rails (4.2.2)
-      actionmailer (= 4.2.2)
-      actionpack (= 4.2.2)
-      actionview (= 4.2.2)
-      activejob (= 4.2.2)
-      activemodel (= 4.2.2)
-      activerecord (= 4.2.2)
-      activesupport (= 4.2.2)
+    rails (4.2.8)
+      actionmailer (= 4.2.8)
+      actionpack (= 4.2.8)
+      actionview (= 4.2.8)
+      activejob (= 4.2.8)
+      activemodel (= 4.2.8)
+      activerecord (= 4.2.8)
+      activesupport (= 4.2.8)
       bundler (>= 1.3.0, < 2.0)
-      railties (= 4.2.2)
+      railties (= 4.2.8)
       sprockets-rails
     rails-deprecated_sanitizer (1.0.3)
       activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.6)
-      activesupport (>= 4.2.0.beta, < 5.0)
-      nokogiri (~> 1.6.0)
+    rails-dom-testing (1.0.9)
+      activesupport (>= 4.2.0, < 5.0)
+      nokogiri (~> 1.6)
       rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.2)
+    rails-html-sanitizer (1.0.3)
       loofah (~> 2.0)
-    railties (4.2.2)
-      actionpack (= 4.2.2)
-      activesupport (= 4.2.2)
+    railties (4.2.8)
+      actionpack (= 4.2.8)
+      activesupport (= 4.2.8)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rake (10.4.2)
     sprockets (3.2.0)
       rack (~> 1.0)
-    sprockets-rails (2.3.2)
+    sprockets-rails (2.3.3)
       actionpack (>= 3.0)
       activesupport (>= 3.0)
       sprockets (>= 2.8, < 4.0)
     sqlite3 (1.3.13)
     sqlite3 (1.3.13-x64-mingw32)
-    thor (0.19.1)
-    thread_safe (0.3.5)
-    tzinfo (1.2.2)
+    thor (0.19.4)
+    thread_safe (0.3.6)
+    tzinfo (1.2.5)
       thread_safe (~> 0.1)
     tzinfo-data (1.2017.3)
       tzinfo (>= 1.0.0)
@@ -110,7 +110,7 @@ PLATFORMS
 
 DEPENDENCIES
   parallel_tests!
-  rails (= 4.2.2)
+  rails (= 4.2.8)
   sqlite3
   tzinfo-data