diff --git a/Gemfile b/Gemfile
index 7da382d..571ebff 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,26 +1,26 @@
 source 'https://rubygems.org'
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '~> 4.2.1'
+gem 'rails', '~> 5.2.4', '>= 5.2.4.2'
 # Use postgresql as the database for Active Record
 gem 'pg'
 # Use SCSS for stylesheets
-gem 'sass-rails', '~> 5.0'
+gem 'sass-rails', '~> 5.0', '>= 5.0.5'
 # Use Uglifier as compressor for JavaScript assets
-gem 'uglifier', '>= 1.3.0'
+gem 'uglifier', '>= 2.7.1'
 # Use CoffeeScript for .coffee assets and views
-gem 'coffee-rails', '~> 4.1.0'
+gem 'coffee-rails', '~> 4.2.2'
 # See https://github.com/rails/execjs#readme for more supported runtimes
 # gem 'therubyracer', platforms: :ruby
 
 # Use jquery as the JavaScript library
-gem 'jquery-rails'
+gem 'jquery-rails', '>= 4.0.3'
 # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
-gem 'turbolinks'
+gem 'turbolinks', '>= 2.5.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem 'jbuilder', '~> 2.0'
+gem 'jbuilder', '~> 2.2', '>= 2.2.12'
 # bundle exec rake doc:rails generates the API under doc/api.
-gem 'sdoc', '~> 0.4.0', group: :doc
+gem 'sdoc', '~> 1.0.0', group: :doc
 
 gem 'rails_12factor', group: :production
 gem 'puma'