diff --git a/modem/msm-modem/APKBUILD b/modem/msm-modem/APKBUILD
index 5f5cd8ce3..a88bb538b 100644
--- a/modem/msm-modem/APKBUILD
+++ b/modem/msm-modem/APKBUILD
@@ -1,5 +1,5 @@
 pkgname=msm-modem
-pkgver=3
+pkgver=4
 pkgrel=0
 pkgdesc="Common support for Qualcomm MSM modems"
 url="https://postmarketos.org/"
@@ -7,8 +7,13 @@ arch="armhf armv7 aarch64"
 license="GPL-3.0-or-later"
 depends="rmtfs rmtfs-openrc"
 install="$pkgname.post-install"
-subpackages="$pkgname-rpmsg $pkgname-downstream"
-source="msm-modem-downstream.initd udev-rpmsg.rules udev-downstream.rules"
+subpackages="$pkgname-rpmsg $pkgname-downstream $pkgname-uim-selection:uim_selection"
+source="
+	msm-modem-downstream.initd
+	msm-modem-uim-selection.initd
+	udev-rpmsg.rules
+	udev-downstream.rules
+"
 options="!check"
 
 package() {
@@ -22,6 +27,14 @@ rpmsg() {
 	install -Dm644 "$srcdir/udev-rpmsg.rules" "$subpkgdir/usr/lib/udev/rules.d/55-$pkgname.rules"
 }
 
+uim_selection() {
+	pkgdesc="$pkgdesc (UIM selection)"
+	depends="$pkgname libqmi"
+	install="$subpkgname.post-install"
+
+	install -Dm755 "$srcdir/$subpkgname.initd" "$subpkgdir/etc/init.d/$subpkgname"
+}
+
 downstream() {
 	pkgdesc="$pkgdesc (downstream)"
 	depends="$pkgname libqipcrtr4msmipc libsmdpkt_wrapper keepfileopen"
@@ -31,6 +44,9 @@ downstream() {
 	install -Dm644 "$srcdir/udev-downstream.rules" "$subpkgdir/usr/lib/udev/rules.d/55-$pkgname.rules"
 }
 
-sha512sums="3172f8c409f552f13d1da29f14ab6c79072cd6da4acab151a1a0ea1858a416974456852609f14fe29cf97a6a45e60b99d0a57ddcde751da243ee5ac6fa8b672c  msm-modem-downstream.initd
+sha512sums="
+3172f8c409f552f13d1da29f14ab6c79072cd6da4acab151a1a0ea1858a416974456852609f14fe29cf97a6a45e60b99d0a57ddcde751da243ee5ac6fa8b672c  msm-modem-downstream.initd
+a68b3887aa24d88faeb84fa0896e1ebff4a2cbe9e71dd5123a517d6b2aba01576469afdc1817b17b7f010e1d33e50409fab3099993c422c01de94405ef98c176  msm-modem-uim-selection.initd
 11437625988fcf57aa0b70f11496c458d4516de16391c2869ae975362f282d21d3af521a41dea00312797d20d52be5112dbf0041986bfb40f3b9fa5948d2c695  udev-rpmsg.rules
-2a511c2e249d0ec5a52f04ffe1ef3d29cf3c4813143b103e54879ff89176ea45b1a5ffe21cb7dc2f1cdd84c3102ba45ef9926ed37e00b1ae12a36d01de35ea5a  udev-downstream.rules"
+2a511c2e249d0ec5a52f04ffe1ef3d29cf3c4813143b103e54879ff89176ea45b1a5ffe21cb7dc2f1cdd84c3102ba45ef9926ed37e00b1ae12a36d01de35ea5a  udev-downstream.rules
+"
diff --git a/modem/msm-modem/msm-modem-uim-selection.initd b/modem/msm-modem/msm-modem-uim-selection.initd
new file mode 100644
index 000000000..5076e6dc4
--- /dev/null
+++ b/modem/msm-modem/msm-modem-uim-selection.initd
@@ -0,0 +1,99 @@
+#!/sbin/openrc-run
+
+# This script tries to automatically configure UIM application for Qualcomm QMI
+# modems with more than one sim slot.
+
+name="UIM Slot selection"
+description="Select UIM slot and application on the embedded QMI nodem."
+
+depend() {
+	# FIXME: This service may delay boot for some time, make sure that it
+	# runs after UI and sshd so preceived boot time isn't affected.
+	after *
+
+	need rmtfs
+	before ofono
+	before modemmanager
+}
+
+# All of the logic is placed in the service start method as we want to block
+# other services while the modem isn't ready yet.
+start() {
+	# libqmi must be present to use this script.
+	if ! [ -x "$(command -v qmicli)" ]
+	then
+		eend 1 'qmicli is not installed.'
+		return 1
+	fi
+
+	# Prepare a qmicli command with desired modem path.
+	# The modem may appear after some delay, wait for it.
+	count=0
+	while [ -z "$QMICLI_MODEM" ] && [ "$count" -lt "45" ]
+	do
+		# Check if legacy rpmsg exported device exists.
+		if [ -e "/dev/modem" ]
+		then
+			QMICLI_MODEM="qmicli --silent -d /dev/modem"
+			veinfo "Using /dev/modem"
+		# Check if the qmi device from wwan driver exists.
+		elif [ -e "/dev/wwan0qmi0" ]
+		then
+			# Using --device-open-qmi flag as we may have libqmi
+			# version that can't automatically detect the type yet.
+			QMICLI_MODEM="qmicli --silent -d /dev/wwan0qmi0 --device-open-qmi"
+			veinfo "Using /dev/wwan0qmi0"
+		# Check if QRTR is available for new devices.
+		elif qmicli --silent -pd qrtr://0 --uim-noop > /dev/null
+		then
+			QMICLI_MODEM="qmicli --silent -pd qrtr://0"
+			veinfo "Using qrtr://0"
+		fi
+		sleep 1
+		count=$((count+1))
+	done
+	veinfo "Waited $count seconds for modem device to appear"
+
+	if [ -z "$QMICLI_MODEM" ]
+	then
+		eend 2 'No modem available.'
+		return 2
+	fi
+
+	QMI_CARDS=$($QMICLI_MODEM --uim-get-card-status)
+
+	# Fail if all slots are empty but wait a bit for the sim to appear.
+	count=0
+	while ! printf "%s" "$QMI_CARDS" | grep -Fq "Card state: 'present'" && [ "$count" -lt "11" ]
+	do
+		sleep 1
+		count=$((count+1))
+		QMI_CARDS=$($QMICLI_MODEM --uim-get-card-status)
+	done
+
+	if [ "$count" -gt "10" ]
+	then
+		eend 4 'No sim present.'
+		return 4
+	fi
+	veinfo "Waited $count seconds for modem to come up"
+
+	# Clear the selected application in case the modem is in a bugged state
+	if ! printf "%s" "$QMI_CARDS" | grep -Fq "Primary GW:   session doesn't exist"
+	then
+		ewarn 'Application was already selected.'
+		$QMICLI_MODEM --uim-change-provisioning-session='activate=no,session-type=primary-gw-provisioning' > /dev/null
+        fi
+
+	# Extract first available slot number and AID for usim application
+	# on it. This should select proper slot out of two if only one UIM is
+	# present or select the first one if both slots have UIM's in them.
+	FIRST_PRESENT_SLOT=$(printf "%s" "$QMI_CARDS" | grep "Card state: 'present'" -m1 -B1 | head -n1 | cut -c7-7)
+	FIRST_PRESENT_AID=$(printf "%s" "$QMI_CARDS" | grep "usim (2)" -m1 -A3 | tail -n1 | awk '{print $1}')
+
+	veinfo "Selecting $FIRST_PRESENT_AID on slot $FIRST_PRESENT_SLOT"
+
+	# Finally send the new configuration to the modem.
+	$QMICLI_MODEM --uim-change-provisioning-session="slot=$FIRST_PRESENT_SLOT,activate=yes,session-type=primary-gw-provisioning,aid=$FIRST_PRESENT_AID" > /dev/null
+	eend $?
+}
diff --git a/modem/msm-modem/msm-modem-uim-selection.post-install b/modem/msm-modem/msm-modem-uim-selection.post-install
new file mode 100644
index 000000000..eae6ed92c
--- /dev/null
+++ b/modem/msm-modem/msm-modem-uim-selection.post-install
@@ -0,0 +1,2 @@
+#!/bin/sh
+rc-update add msm-modem-uim-selection default