diff --git a/Gemfile b/Gemfile
index 3ea67cb..ad43182 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-ruby '>=2.3'
+ruby '2.3.1'
 
 gem 'scraperwiki', :git => 'https://github.com/openaustralia/scraperwiki-ruby/', :branch => 'morph_defaults'
 gem 'petrify', '>= 0.4.0'