diff --git a/.travis.yml b/.travis.yml
index d69c37b4..f086443b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,12 @@
 language: ruby
 
 rvm:
-  - 2.2.2
-  - 2.4.0
-
+  - 2.2
+  - 2.4
+  - 2.5
+  - 2.6
+before_install:
+  - gem install bundler
 os:
 - linux
 - osx
diff --git a/Gemfile b/Gemfile
index d345ad96..b2494c22 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,16 +1,16 @@
-source "http://rubygems.org"
+source "https://rubygems.org"
 
-gem 'rake', '~> 10'
+gem 'rake', '~> 10.0'
 gem 'rspec-collection_matchers', '~> 1.1'
 gem 'rdoc', '~> 4.2'
 gem 'simplecov', :platforms => :mri_19
 
 group :multipart_support do
-  gem 'multipart-post', '~> 2'
+  gem 'multipart-post', '~> 2.0'
 end
 
 group :nokogiri do
-  gem 'nokogiri', '~> 1'
+  gem 'nokogiri', '~> 1.0'
 end
 
 group :libxml do
@@ -20,11 +20,11 @@ group :libxml do
 end
 
 group :memcached_support do
-  gem 'dalli', '~> 2'
+  gem 'dalli', '~> 2.0'
 end
 
 group :redis_support do
-  gem 'redis', '~> 3'
+  gem 'redis', '~> 3.0'
 end
 
 group :eventmachine_support do