diff --git a/scripts/fetch_markdown_files.sh b/scripts/fetch_markdown_files.sh
--- a/scripts/fetch_markdown_files.sh
+++ b/scripts/fetch_markdown_files.sh
@@ -1,8 +1,11 @@
+#!/usr/bin/env bash
 # Pull all the markdown files from the ABC repository so they can be converted
 # and rendered by jekyll. The tree directory structure is preserved in order to
 # keep the links working.
 # The path to the ABC repository must be passed as a command line argument.
 
+set -euxo pipefail
+
 SRC_DIR=$1
 
 SCRIPT_DIR=$(cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd)