diff --git a/.travis.yml b/.travis.yml
index 1f585ea..6a82d57 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,11 +1,11 @@
 language: ruby
 sudo: false
 rvm:
-- "2.0"
-- "2.1"
-- "2.2"
-- "2.3.4"
-- "2.4.1"
+- "2.3.8"
+- "2.4.10"
+- "2.5.8"
+- "2.6.6"
+- "2.7.1"
 - ruby-head
 - jruby-head
 matrix:
diff --git a/binary_struct.gemspec b/binary_struct.gemspec
index 93c70fd..6c36313 100644
--- a/binary_struct.gemspec
+++ b/binary_struct.gemspec
@@ -25,9 +25,9 @@ from/to a Hash.
   spec.test_files   += %w[.rspec]
   spec.require_paths = ["lib"]
 
-  spec.required_ruby_version = '>= 1.9.3'
+  spec.required_ruby_version = '>= 2.3'
 
-  spec.add_development_dependency "bundler", "~> 1.3"
+  spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec", ">= 3.0"
   spec.add_development_dependency "coveralls"