diff --git a/maint/update-authors.sh b/maint/update-authors.sh
index 9718811e..c8d5c3f4 100755
--- a/maint/update-authors.sh
+++ b/maint/update-authors.sh
@@ -1,3 +1,4 @@
+#!/bin/sh
 # Copyright 2010 Lennart Poettering
 # Copyright 2022 Simon McVittie
 # SPDX-License-Identifier: MIT