diff --git a/lib/ruby_dep/travis.rb b/lib/ruby_dep/travis.rb
index 5176a5a..d11b193 100644
--- a/lib/ruby_dep/travis.rb
+++ b/lib/ruby_dep/travis.rb
@@ -1,3 +1,4 @@
+require 'tmpdir'
 require 'yaml'
 
 require 'ruby_dep/travis/ruby_version'