diff --git a/pkg/kamailio/deb/buster/kamailio.default b/pkg/kamailio/deb/buster/kamailio.default
index 8b20fc00358..c00754f0a4d 100644
--- a/pkg/kamailio/deb/buster/kamailio.default
+++ b/pkg/kamailio/deb/buster/kamailio.default
@@ -5,11 +5,12 @@
 # Set to yes to enable kamailio, once configured properly.
 #RUN_KAMAILIO=yes
 
-# User to run as
-#USER=kamailio
-
-# Group to run as
-#GROUP=kamailio
+# To change username or group please create drop-in /etc/systemd/system/kamailio.service.d/10-user_group.conf file, like
+# ```
+# [Service]
+# User=kamuser
+# Group=kamgroup
+# ```
 
 # Amount of shared and private memory to allocate
 # for the running Kamailio server (in Mb)
diff --git a/pkg/kamailio/deb/buster/kamailio.service b/pkg/kamailio/deb/buster/kamailio.service
index 4575fde6153..6e3a7256971 100644
--- a/pkg/kamailio/deb/buster/kamailio.service
+++ b/pkg/kamailio/deb/buster/kamailio.service
@@ -4,18 +4,16 @@ Wants=network-online.target
 After=network-online.target
 
 [Service]
-Type=forking
+Type=simple
+User=kamailio
+Group=kamailio
 Environment='CFGFILE=/etc/kamailio/kamailio.cfg'
 Environment='SHM_MEMORY=64'
 Environment='PKG_MEMORY=8'
-Environment='USER=kamailio'
-Environment='GROUP=kamailio'
 EnvironmentFile=-/etc/default/kamailio
 EnvironmentFile=-/etc/default/kamailio.d/*
-# PIDFile requires a full absolute path
-PIDFile=/var/run/kamailio/kamailio.pid
 # ExecStart requires a full absolute path
-ExecStart=/usr/sbin/kamailio -P /var/run/kamailio/kamailio.pid -f $CFGFILE -m $SHM_MEMORY -M $PKG_MEMORY -u $USER -g $GROUP
+ExecStart=/usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f $CFGFILE -m $SHM_MEMORY -M $PKG_MEMORY
 Restart=on-failure
 # /var/run/kamailio in tmpfs
 RuntimeDirectory=kamailio
diff --git a/pkg/kamailio/deb/buster/kamailio.tmpfiles b/pkg/kamailio/deb/buster/kamailio.tmpfiles
new file mode 100644
index 00000000000..77503ab7483
--- /dev/null
+++ b/pkg/kamailio/deb/buster/kamailio.tmpfiles
@@ -0,0 +1 @@
+D /run/kamailio 0750 kamailio kamailio -