diff --git a/website/Gemfile b/website/Gemfile
index 29ff7e53c..d270a5ae4 100644
--- a/website/Gemfile
+++ b/website/Gemfile
@@ -1,5 +1,7 @@
 source 'https://rubygems.org'
 
+ruby '1.9.3'
+
 gem "middleman", "~> 3.0.6"
 gem "middleman-minify-html", "~> 3.0.0"
 gem "rack-contrib", "~> 1.1.0"