diff --git a/Gemfile b/Gemfile
index 9e2837a..ce5fece 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,11 @@
-source :rubygems
+source 'https://rubygems.org'
+
+if ENV.key?('PUPPET_VERSION')
+  puppetversion = "= #{ENV['PUPPET_VERSION']}"
+else
+  puppetversion = "~> 3.4.1"
+end
+
 gem 'rake'
+gem 'puppet', puppetversion
 gem 'puppet-lint'