diff --git a/.travis.yml b/.travis.yml
index b747b71..5551af1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,23 +3,11 @@ script: bundle exec rake test
 sudo: false
 
 rvm:
-- "1.9"
-- "2.0"
-- "2.1"
-- "2.2.2"
+- 2.2
+- 2.3
+- 2.4
 
 gemfile:
-- Gemfile.activesupport32
-- Gemfile.activesupport40
-- Gemfile.activesupport41
 - Gemfile.activesupport42
 - Gemfile.activesupport50
-
-matrix:
-  exclude:
-    - rvm: "1.9"
-      gemfile: Gemfile.activesupport50
-    - rvm: "2.0"
-      gemfile: Gemfile.activesupport50
-    - rvm: "2.1"
-      gemfile: Gemfile.activesupport50
+- Gemfile.activesupport51
diff --git a/Gemfile.activesupport40 b/Gemfile.activesupport40
deleted file mode 100644
index 50a93e9..0000000
--- a/Gemfile.activesupport40
+++ /dev/null
@@ -1,4 +0,0 @@
-source "https://rubygems.org"
-gemspec
-
-gem 'activesupport', '~> 4.0.0'
diff --git a/Gemfile.activesupport41 b/Gemfile.activesupport41
deleted file mode 100644
index 425b6f8..0000000
--- a/Gemfile.activesupport41
+++ /dev/null
@@ -1,4 +0,0 @@
-source "https://rubygems.org"
-gemspec
-
-gem 'activesupport', '~> 4.1.0'
diff --git a/Gemfile.activesupport32 b/Gemfile.activesupport51
similarity index 54%
rename from Gemfile.activesupport32
rename to Gemfile.activesupport51
index 1e87734..bcc1ce3 100644
--- a/Gemfile.activesupport32
+++ b/Gemfile.activesupport51
@@ -1,4 +1,4 @@
 source "https://rubygems.org"
 gemspec
 
-gem 'activesupport', '~> 3.2.0'
+gem 'activesupport', '~> 5.1.0'
diff --git a/active_utils.gemspec b/active_utils.gemspec
index 373d779..4200ea3 100644
--- a/active_utils.gemspec
+++ b/active_utils.gemspec
@@ -14,7 +14,8 @@ Gem::Specification.new do |s|
 
   s.rubyforge_project = "active_utils"
 
-  s.add_dependency('activesupport', '>= 3.2', '< 5.2.0')
+  s.required_ruby_version = '>= 2.2'
+  s.add_dependency('activesupport', '>= 4.2', '< 5.2.0')
   s.add_dependency('i18n')
 
   s.add_development_dependency('rake')