diff --git a/Gemfile b/Gemfile
index 9a5789a16..4a0073c5a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
+ruby '1.8.7'
 
 gem 'webby', '~> 0.9.4'
 gem 'coderay', '~> 0.9.8'