diff --git a/Gemfile b/Gemfile
index 851fabc..1ca2f50 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,2 +1,6 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
+
+# Specify your gem's dependencies in digest-blake2b.gemspec
 gemspec
diff --git a/Rakefile b/Rakefile
index 7ac8513..7a9d493 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rake/testtask'
 require 'rake/extensiontask'
diff --git a/digest-blake2b.gemspec b/digest-blake2b.gemspec
index 940be67..021133e 100644
--- a/digest-blake2b.gemspec
+++ b/digest-blake2b.gemspec
@@ -15,7 +15,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '~> 2.1'
 
-  spec.authors = ['Franck Verrot', 'Mauricio Gomes']
+  spec.authors = ['Alex Kotov', 'Franck Verrot', 'Mauricio Gomes']
   spec.email   = %w[mauricio@edge14.com]
 
   spec.description = <<-DESCRIPTION.split.join ' '
@@ -43,8 +43,8 @@ Gem::Specification.new do |spec|
 
   spec.extensions << 'ext/digest/blake2b_ext/extconf.rb'
 
-  spec.add_development_dependency 'rake-compiler', '~> 0.9'
-  spec.add_development_dependency 'bundler'      , '~> 1.5'
-  spec.add_development_dependency 'rake'         , '~> 11.1'
+  spec.add_development_dependency 'bundler'      , '~> 2.2'
   spec.add_development_dependency 'minitest'     , '~> 5.11'
+  spec.add_development_dependency 'rake'         , '~> 13.0'
+  spec.add_development_dependency 'rake-compiler', '~> 0.9'
 end