diff --git a/buildroot-external/overlay/base/etc/profile.d/umask.sh b/buildroot-external/overlay/base/etc/profile.d/umask.sh
index 032f1e5b89..06de142b7b 100644
--- a/buildroot-external/overlay/base/etc/profile.d/umask.sh
+++ b/buildroot-external/overlay/base/etc/profile.d/umask.sh
@@ -1 +1,3 @@
+#!/bin/sh
+# shellcheck shell=dash
 umask 0002
diff --git a/buildroot-external/package/recovery-system/external/overlay/base/etc/profile.d/umask.sh b/buildroot-external/package/recovery-system/external/overlay/base/etc/profile.d/umask.sh
index 032f1e5b89..06de142b7b 100644
--- a/buildroot-external/package/recovery-system/external/overlay/base/etc/profile.d/umask.sh
+++ b/buildroot-external/package/recovery-system/external/overlay/base/etc/profile.d/umask.sh
@@ -1 +1,3 @@
+#!/bin/sh
+# shellcheck shell=dash
 umask 0002