diff --git a/image/mkosi.postinst b/image/mkosi.postinst
index 83d19c8b1..fdd37c658 100755
--- a/image/mkosi.postinst
+++ b/image/mkosi.postinst
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/env bash
 set -euxo pipefail
 
 # This will work in sd-boot 251 to auto-enroll secure boot keys.
diff --git a/image/mkosi.prepare b/image/mkosi.prepare
index 150d26fb2..deb744868 100755
--- a/image/mkosi.prepare
+++ b/image/mkosi.prepare
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/env bash
 set -euxo pipefail
 
 # set selinux to permissive