diff --git a/.rubocop.yml b/.rubocop.yml
index fd35fb63..899ceb0c 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.5
   Exclude:
     - 'tmp/**/*'
     - 'vendor/bundle/**/*'
diff --git a/.travis.yml b/.travis.yml
index 4bc7ec38..39bde42e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,8 +6,6 @@ rvm:
 - 2.7.0
 - 2.6.5
 - 2.5.7
-- 2.4.9
-- 2.3.8
 - jruby-9.2.11.0
 - rbx-4
 jobs:
diff --git a/i18n-tasks.gemspec b/i18n-tasks.gemspec
index 58ca7d29..c29a6aa2 100644
--- a/i18n-tasks.gemspec
+++ b/i18n-tasks.gemspec
@@ -25,7 +25,7 @@ TEXT
 TEXT
   s.homepage = 'https://github.com/glebm/i18n-tasks'
   s.metadata = { 'issue_tracker' => 'https://github.com/glebm/i18n-tasks' } if s.respond_to?(:metadata=)
-  s.required_ruby_version = '>= 2.3', '< 4.0' if s.respond_to?(:required_ruby_version=)
+  s.required_ruby_version = '>= 2.5', '< 4.0' if s.respond_to?(:required_ruby_version=)
 
   s.files = `git ls-files`.split($/)
   s.files -= s.files.grep(%r{^(doc/|\.|spec/)}) + %w[CHANGES.md config/i18n-tasks.yml Gemfile]