diff --git a/conf/nginx-top.conf b/conf/nginx-top.conf
index c3f4c0d69..6e01e3d52 100644
--- a/conf/nginx-top.conf
+++ b/conf/nginx-top.conf
@@ -7,6 +7,6 @@
 ##       your own --- please do not ask for help from us.
 
 upstream php-fpm {
-	server unix:/var/run/php/php8.0-fpm.sock;
+	server unix:/var/run/php/php8.1-fpm.sock;
 }
 
diff --git a/management/backup.py b/management/backup.py
index aae6c00b8..34091601b 100755
--- a/management/backup.py
+++ b/management/backup.py
@@ -296,7 +296,7 @@ def service_command(service, command, quit=None):
 			if quit:
 				sys.exit(code)
 
-	service_command("php8.0-fpm", "stop", quit=True)
+	service_command("php8.1-fpm", "stop", quit=True)
 	service_command("postfix", "stop", quit=True)
 	service_command("dovecot", "stop", quit=True)
 	service_command("postgrey", "stop", quit=True)
@@ -333,7 +333,7 @@ def service_command(service, command, quit=None):
 		service_command("postgrey", "start", quit=False)
 		service_command("dovecot", "start", quit=False)
 		service_command("postfix", "start", quit=False)
-		service_command("php8.0-fpm", "start", quit=False)
+		service_command("php8.1-fpm", "start", quit=False)
 
 	# Remove old backups. This deletes all backup data no longer needed
 	# from more than 3 days ago.
diff --git a/setup/functions.sh b/setup/functions.sh
index 6a96cc1f8..85925e6c3 100644
--- a/setup/functions.sh
+++ b/setup/functions.sh
@@ -5,7 +5,7 @@
 # -o pipefail: don't ignore errors in the non-last command in a pipeline
 set -euo pipefail
 
-PHP_VER=8.0
+PHP_VER=8.1
 
 function hide_output {
 	# This function hides the output of a command unless the command fails
diff --git a/setup/nextcloud.sh b/setup/nextcloud.sh
index 496ca0c02..104983c0c 100755
--- a/setup/nextcloud.sh
+++ b/setup/nextcloud.sh
@@ -90,6 +90,24 @@ InstallNextcloud() {
 	echo "Upgrading to Nextcloud version $version"
 	echo
 
+	# set PHP version, set to earlier version if required for upgrade
+	nc_php_ver="$PHP_VER"
+	if [[ ${version} =~ ^2[0123] ]]; then
+		nc_php_ver=8.0
+	fi
+
+	# install earlier PHP version 
+	if [ "$nc_php_ver" != "$PHP_VER" ]; then
+		apt_install curl php"${nc_php_ver}" php"${nc_php_ver}"-fpm \
+			php"${nc_php_ver}"-cli php"${nc_php_ver}"-sqlite3 php"${nc_php_ver}"-gd php"${nc_php_ver}"-imap php"${nc_php_ver}"-curl \
+			php"${nc_php_ver}"-dev php"${nc_php_ver}"-gd php"${nc_php_ver}"-xml php"${nc_php_ver}"-mbstring php"${nc_php_ver}"-zip php"${nc_php_ver}"-apcu \
+			php"${nc_php_ver}"-intl php"${nc_php_ver}"-imagick php"${nc_php_ver}"-gmp php"${nc_php_ver}"-bcmath
+		
+		tools/editconf.py /etc/php/"$nc_php_ver"/mods-available/apcu.ini -c ';' \
+			apc.enabled=1 \
+			apc.enable_cli=1
+	fi
+
 	# Download and verify
 	wget_verify "https://download.nextcloud.com/server/releases/nextcloud-$version.zip" "$hash" /tmp/nextcloud.zip
 
@@ -138,23 +156,23 @@ InstallNextcloud() {
 	if [ -e "$STORAGE_ROOT/owncloud/owncloud.db" ]; then
 		# ownCloud 8.1.1 broke upgrades. It may fail on the first attempt, but
 		# that can be OK.
-		sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ upgrade
+		sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ upgrade
 		E=$?
 		if [ $E -ne 0 ] && [ $E -ne 3 ]; then
 			echo "Trying ownCloud upgrade again to work around ownCloud upgrade bug..."
-			sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ upgrade
+			sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ upgrade
 			E=$?
 			if [ $E -ne 0 ] && [ $E -ne 3 ]; then exit 1; fi
-			sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ maintenance:mode --off
+			sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ maintenance:mode --off
 			echo "...which seemed to work."
 		fi
 
 		# Add missing indices. NextCloud didn't include this in the normal upgrade because it might take some time.
-		sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ db:add-missing-indices
-		sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ db:add-missing-primary-keys
+		sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ db:add-missing-indices
+		sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ db:add-missing-primary-keys
 
 		# Run conversion to BigInt identifiers, this process may take some time on large tables.
-		sudo -u www-data php"$PHP_VER" /usr/local/lib/owncloud/occ db:convert-filecache-bigint --no-interaction
+		sudo -u www-data php"$nc_php_ver" /usr/local/lib/owncloud/occ db:convert-filecache-bigint --no-interaction
 	fi
 }
 
diff --git a/tools/owncloud-restore.sh b/tools/owncloud-restore.sh
index 05d576415..6b3f3e92f 100755
--- a/tools/owncloud-restore.sh
+++ b/tools/owncloud-restore.sh
@@ -26,7 +26,7 @@ if [ ! -f "$1/config.php" ]; then
 fi
 
 echo "Restoring backup from $1"
-service php8.0-fpm stop
+service php8.1-fpm stop
 
 # remove the current ownCloud/Nextcloud installation
 rm -rf /usr/local/lib/owncloud/
@@ -45,5 +45,5 @@ chown www-data:www-data "$STORAGE_ROOT/owncloud/config.php"
 
 sudo -u www-data "php$PHP_VER" /usr/local/lib/owncloud/occ maintenance:mode --off
 
-service php8.0-fpm start
+service php8.1-fpm start
 echo "Done"