diff --git a/btest b/btest
index ac33bb24..378a4784 100755
--- a/btest
+++ b/btest
@@ -177,6 +177,7 @@ def ExpandBackticks(origvalue):
         if not cmd:
             return ""
 
+        tf_name = None
         if sys.platform == 'win32':
             try:
                 tf, tf_name = tempfile.mkstemp(suffix='.sh')