diff --git a/lib/tilt/pdf.rb b/lib/tilt/pdf.rb
index 2ea25e5..1baf58c 100644
--- a/lib/tilt/pdf.rb
+++ b/lib/tilt/pdf.rb
@@ -2,6 +2,7 @@ require 'pdfkit'
 require 'tilt'
 require 'tilt/template'
 require 'yaml'
+require 'tempfile'
 
 module Tilt
   class PDFTemplate < Template