diff -Nru isc-dhcp-4.4.1/debian/changelog isc-dhcp-4.4.1/debian/changelog
--- isc-dhcp-4.4.1/debian/changelog	2021-05-27 06:59:48.000000000 +0200
+++ isc-dhcp-4.4.1/debian/changelog	2022-04-08 20:56:46.000000000 +0200
@@ -1,3 +1,10 @@
+isc-dhcp (4.4.1-2.4) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * Ignore stale pidfile in /etc/init.d/isc-dhcp-server on start.
+
+ -- H.-Dirk Schmitt <dirk@computer42.org>  Fri, 08 Apr 2022 20:56:46 +0200
+
 isc-dhcp (4.4.1-2.3) unstable; urgency=high
 
   * Non-maintainer upload.
diff -Nru isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d
--- isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d	2021-05-27 06:59:48.000000000 +0200
+++ isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d	2022-04-08 20:56:46.000000000 +0200
@@ -100,8 +100,12 @@
 	log_daemon_msg "Starting $DESC" "$NAME"
 
 	if [ -e "$PIDFILE" ]; then
-		log_failure_msg "dhcpd service already running (pid file $PIDFILE currenty exists)"
-		exit 1
+		if ps -p "$pid" > /dev/null 2>&1; then
+			log_failure_msg "dhcpd service already running (pid file $PIDFILE currenty exists)"
+			exit 1
+		else
+			echo "ingore stale pid file $PIDFILE"
+		fi
 	fi
 
 	touch /var/lib/dhcp/$NAME.leases
diff -Nru isc-dhcp-4.4.1/debian/patches/fix-initd-stale-pidfile.patch isc-dhcp-4.4.1/debian/patches/fix-initd-stale-pidfile.patch
--- isc-dhcp-4.4.1/debian/patches/fix-initd-stale-pidfile.patch	1970-01-01 01:00:00.000000000 +0100
+++ isc-dhcp-4.4.1/debian/patches/fix-initd-stale-pidfile.patch	2022-04-08 20:56:46.000000000 +0200
@@ -0,0 +1,19 @@
+Index: isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d
+===================================================================
+--- isc-dhcp-4.4.1.orig/debian/isc-dhcp-server.init.d
++++ isc-dhcp-4.4.1/debian/isc-dhcp-server.init.d
+@@ -100,8 +100,12 @@ start_daemon()
+ 	log_daemon_msg "Starting $DESC" "$NAME"
+ 
+ 	if [ -e "$PIDFILE" ]; then
+-		log_failure_msg "dhcpd service already running (pid file $PIDFILE currenty exists)"
+-		exit 1
++		if ps -p "$pid" > /dev/null 2>&1; then
++			log_failure_msg "dhcpd service already running (pid file $PIDFILE currenty exists)"
++			exit 1
++		else
++			echo "ingore stale pid file $PIDFILE"
++		fi
+ 	fi
+ 
+ 	touch /var/lib/dhcp/$NAME.leases