diff --git a/Gemfile b/Gemfile
index f23df36b9..7e45a9d33 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
+ruby '2.4.0'
 
 gem 'rails', '~> 5.0.0', '>= 5.0.0.1'
 gem 'sass-rails', '~> 5.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 4c1eb3574..8cbb9733d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -487,5 +487,8 @@ DEPENDENCIES
   webpacker
   wisper (= 2.0.0)
 
+RUBY VERSION
+   ruby 2.4.0p0
+
 BUNDLED WITH
    1.17.3