diff --git a/cli.py b/cli.py
index e6f2df8..863762b 100644
--- a/cli.py
+++ b/cli.py
@@ -348,7 +348,7 @@ class CLI(object):
                 try:
                     for line in file(self.options.part):
                         elements = line.strip().split(' ')
-                       if not elements[3]:
+                       if len(elements) < 3:
                                tmpfile = util.tmp_filename(tmp_root=self.options.tmp_root)
                        else:
                                tmpfile = elements[3]