diff --git a/vendor/plugins/rfpdf/lib/tcpdf.rb b/vendor/plugins/rfpdf/lib/tcpdf.rb
index ee8cba91c..0013ca66a 100755
--- a/vendor/plugins/rfpdf/lib/tcpdf.rb
+++ b/vendor/plugins/rfpdf/lib/tcpdf.rb
@@ -82,10 +82,10 @@ class TCPDF
   @@k_small_ratio = 2/3.0
   
   cattr_accessor :k_path_cache
-  @@k_path_cache = File.join(RAILS_ROOT, 'tmp')
+  @@k_path_cache = Rails.root.join('tmp')
   
   cattr_accessor :k_path_url_cache
-  @@k_path_url_cache = File.join(RAILS_ROOT, 'tmp')
+  @@k_path_url_cache = Rails.root.join('tmp')
   
   cattr_accessor :decoder