diff --git a/stack-build.sh b/stack-build.sh
index 2344ff5..d3a3acc 100755
--- a/stack-build.sh
+++ b/stack-build.sh
@@ -1,4 +1,7 @@
-set -ex
+#!/bin/bash
+
+set -e
+
 for n in 1143 1145 1135 9274
 do
 	perl stack-years.pl $n >$n-pivot.txt