diff --git a/util/mkblankimage.sh b/util/mkblankimage.sh
index 43a3cca293..e764ea45b8 100755
--- a/util/mkblankimage.sh
+++ b/util/mkblankimage.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 #
 # makeblankimage.sh
 # Make a blank M5 disk image