1 files changed, 2 insertions, 1 deletions
diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index bf51ac2788..ed376a5032 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -28,13 +28,14 @@ class Tempfile < SimpleDelegator
     }
   end
 
-  def initialize(basename, tmpdir = '/tmp')
+  def initialize(basename, tmpdir = nil)
     umask = File.umask(0177)
     tmpname = lock = nil
     begin
       n = 0
       while true
 	begin
+	  tmpdir ||= ENV['TMPDIR'] || ENV['TMP'] || ENV['TEMP'] || '/tmp'
 	  tmpname = sprintf('%s/%s.%d.%d', tmpdir, basename, $$, n)
 	  lock = tmpname + '.lock'
 	  unless File.exist?(lock)