diff --git a/patches/october_2012/find_wrong_voucher.py b/patches/october_2012/find_wrong_voucher.py
index 189f2b6..637ed1d 100644
--- a/patches/october_2012/find_wrong_voucher.py
+++ b/patches/october_2012/find_wrong_voucher.py
@@ -12,5 +12,5 @@
 	for d in vouchers:
 		total_tax = webnotes.conn.sql("""select total_tax from `tab%s` where name = %s""" %
 			(d[1], '%s'), d[0])
-		if flt(total_tax[0][0]) != flt(d[3]):
+		if total_tax and flt(total_tax[0][0]) != flt(d[3]):
 			print d
\ No newline at end of file