diff --git a/build/portal/graphs/make-collectd-graphs.sh b/build/portal/graphs/make-collectd-graphs.sh
index 8efbdd6..9ea1050 100644
--- a/build/portal/graphs/make-collectd-graphs.sh
+++ b/build/portal/graphs/make-collectd-graphs.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Assign the Lighthttpd document root directory to a variable.
 RAWDOCUMENTROOT=`/usr/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf -p | grep server.document-root`