diff --git a/plist b/plist
index 22cdd63e4..760d68bb6 100644
--- a/plist
+++ b/plist
@@ -149,6 +149,7 @@
 /usr/local/etc/rc.syshook.d/stop/90-backup
 /usr/local/etc/rc.syshook.d/stop/99-config
 /usr/local/etc/rc.syshook.d/update/10-refresh
+/usr/local/etc/rc.syshook.d/upgrade/20-squid-plugin.php
 /usr/local/etc/rc.syshook.d/upgrade/20-unbound-duckdb.py
 /usr/local/etc/ssl/opnsense.cnf
 /usr/local/etc/strongswan.opnsense.d/README
diff --git a/src/etc/rc.syshook.d/upgrade/20-squid-plugin.php b/src/etc/rc.syshook.d/upgrade/20-squid-plugin.php
new file mode 100755
index 000000000..be10abdd2
--- /dev/null
+++ b/src/etc/rc.syshook.d/upgrade/20-squid-plugin.php
@@ -0,0 +1,41 @@
+#!/usr/local/bin/php
+<?php
+
+/*
+ * Copyright (C) 2024 Deciso B.V.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+require_once 'config.inc';
+require_once 'util.inc';
+
+if (
+    isset($config['OPNsense']['proxy']['general']['enabled']) &&
+    $config['OPNsense']['proxy']['general']['enabled'] == 1
+) {
+    echo 'Squid web proxy is active. Installing replacement plugin...' . PHP_EOL;
+    passthru('/usr/local/opnsense/scripts/firmware/launcher.sh -u install os-squid');
+} else {
+    echo 'Squid web proxy is not active. Not installing replacement plugin.' . PHP_EOL;
+}
diff --git a/src/opnsense/scripts/firmware/install.sh b/src/opnsense/scripts/firmware/install.sh
index 8c858209e..a20905db4 100755
--- a/src/opnsense/scripts/firmware/install.sh
+++ b/src/opnsense/scripts/firmware/install.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright (C) 2015-2021 Franco Fichtner <franco@opnsense.org>
+# Copyright (C) 2015-2024 Franco Fichtner <franco@opnsense.org>
 # Copyright (C) 2014 Deciso B.V.
 # All rights reserved.
 #
@@ -27,6 +27,7 @@
 
 LOCKFILE=/tmp/pkg_upgrade.progress
 PACKAGE=${1}
+TEE="/usr/bin/tee -a"
 
 : > ${LOCKFILE}
 
@@ -40,14 +41,14 @@ if [ "${PACKAGE#os-}" != "${PACKAGE}" ]; then
 
 	# plugins must pass a version check on up-to-date core package
 	if [ "$(pkg version -t ${COREVER} ${REPOVER})" = "<" ]; then
-		echo "Installation out of date. The update to ${COREPKG}-${REPOVER} is required." >> ${LOCKFILE} 2>&1
+		echo "Installation out of date. The update to ${COREPKG}-${REPOVER} is required." | ${TEE} ${LOCKFILE}
 		echo '***DONE***' >> ${LOCKFILE}
 		exit
 	fi
 fi
 
-pkg install -y ${PACKAGE} >> ${LOCKFILE} 2>&1
-/usr/local/opnsense/scripts/firmware/register.php install ${PACKAGE} >> ${LOCKFILE} 2>&1
-pkg autoremove -y >> ${LOCKFILE} 2>&1
+(pkg install -y ${PACKAGE} 2>&1) | ${TEE} ${LOCKFILE}
+(/usr/local/opnsense/scripts/firmware/register.php install ${PACKAGE} 2>&1) | ${TEE} ${LOCKFILE}
+(pkg autoremove -y 2>&1) | ${TEE} ${LOCKFILE}
 
 echo '***DONE***' >> ${LOCKFILE}