diff --git a/etc/inc/allow-bin-sh.inc b/etc/inc/allow-bin-sh.inc
new file mode 100644
index 000000000..d6c295414
--- /dev/null
+++ b/etc/inc/allow-bin-sh.inc
@@ -0,0 +1,7 @@
+# This file is overwritten during software install.
+# Persistent customizations should go in a .local file.
+include allow-bin-sh.local
+
+noblacklist ${PATH}/bash
+noblacklist ${PATH}/dash
+noblacklist ${PATH}/sh
diff --git a/etc/profile-m-z/mpv.profile b/etc/profile-m-z/mpv.profile
index 1d87eeb48..7111febc2 100644
--- a/etc/profile-m-z/mpv.profile
+++ b/etc/profile-m-z/mpv.profile
@@ -21,7 +21,7 @@ include globals.local
 #  - ...
 #
 # Often these scripts require a shell:
-#noblacklist ${PATH}/sh
+#include allow-bin-sh.inc
 #private-bin sh
 
 noblacklist ${HOME}/.config/mpv
diff --git a/etc/profile-m-z/nodejs-common.profile b/etc/profile-m-z/nodejs-common.profile
index acef622c2..c12fc9a78 100644
--- a/etc/profile-m-z/nodejs-common.profile
+++ b/etc/profile-m-z/nodejs-common.profile
@@ -12,9 +12,7 @@ blacklist ${RUNUSER}
 
 ignore noexec ${HOME}
 
-noblacklist ${PATH}/bash
-noblacklist ${PATH}/dash
-noblacklist ${PATH}/sh
+include allow-bin-sh.inc
 
 include disable-common.inc
 include disable-exec.inc