diff --git a/modem/msm-modem/APKBUILD b/modem/msm-modem/APKBUILD
index b823d56fd..5f5cd8ce3 100644
--- a/modem/msm-modem/APKBUILD
+++ b/modem/msm-modem/APKBUILD
@@ -1,5 +1,5 @@
 pkgname=msm-modem
-pkgver=2
+pkgver=3
 pkgrel=0
 pkgdesc="Common support for Qualcomm MSM modems"
 url="https://postmarketos.org/"
@@ -8,7 +8,7 @@ license="GPL-3.0-or-later"
 depends="rmtfs rmtfs-openrc"
 install="$pkgname.post-install"
 subpackages="$pkgname-rpmsg $pkgname-downstream"
-source="udev-rpmsg.rules udev-downstream.rules"
+source="msm-modem-downstream.initd udev-rpmsg.rules udev-downstream.rules"
 options="!check"
 
 package() {
@@ -24,10 +24,13 @@ rpmsg() {
 
 downstream() {
 	pkgdesc="$pkgdesc (downstream)"
-	depends="$pkgname libqipcrtr4msmipc libsmdpkt_wrapper"
+	depends="$pkgname libqipcrtr4msmipc libsmdpkt_wrapper keepfileopen"
+	install="$subpkgname.post-install"
 
+	install -Dm755 "$srcdir/$subpkgname.initd" "$subpkgdir/etc/init.d/$subpkgname"
 	install -Dm644 "$srcdir/udev-downstream.rules" "$subpkgdir/usr/lib/udev/rules.d/55-$pkgname.rules"
 }
 
-sha512sums="11437625988fcf57aa0b70f11496c458d4516de16391c2869ae975362f282d21d3af521a41dea00312797d20d52be5112dbf0041986bfb40f3b9fa5948d2c695  udev-rpmsg.rules
+sha512sums="3172f8c409f552f13d1da29f14ab6c79072cd6da4acab151a1a0ea1858a416974456852609f14fe29cf97a6a45e60b99d0a57ddcde751da243ee5ac6fa8b672c  msm-modem-downstream.initd
+11437625988fcf57aa0b70f11496c458d4516de16391c2869ae975362f282d21d3af521a41dea00312797d20d52be5112dbf0041986bfb40f3b9fa5948d2c695  udev-rpmsg.rules
 2a511c2e249d0ec5a52f04ffe1ef3d29cf3c4813143b103e54879ff89176ea45b1a5ffe21cb7dc2f1cdd84c3102ba45ef9926ed37e00b1ae12a36d01de35ea5a  udev-downstream.rules"
diff --git a/modem/msm-modem/msm-modem-downstream.initd b/modem/msm-modem/msm-modem-downstream.initd
new file mode 100644
index 000000000..114e643c8
--- /dev/null
+++ b/modem/msm-modem/msm-modem-downstream.initd
@@ -0,0 +1,21 @@
+#!/sbin/openrc-run
+supervisor=supervise-daemon
+
+name="Modem Subsystem"
+description="Qualcomm MSM modem subsystem service"
+
+_subsys="/dev/subsys_modem"
+command="/usr/bin/keepfileopen"
+command_args="$_subsys"
+
+respawn_delay=1
+respawn_max=3
+
+depend() {
+	need rmtfs
+}
+
+start() {
+	# Subsystem misc file is only available on some downstream kernels
+	[ ! -c "$_subsys" ] || default_start
+}
diff --git a/modem/msm-modem/msm-modem-downstream.post-install b/modem/msm-modem/msm-modem-downstream.post-install
new file mode 100644
index 000000000..255ad8936
--- /dev/null
+++ b/modem/msm-modem/msm-modem-downstream.post-install
@@ -0,0 +1,2 @@
+#!/bin/sh
+rc-update add msm-modem-downstream