PAMName=systemd-user
Type=notify
ExecStart=-@rootlibexecdir@/systemd --user
-Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/%I/dbus/user_bus_socket
+m4_ifdef(`ENABLE_KDBUS',
+Environment=DBUS_SESSION_BUS_ADDRESS=kernel:path=/dev/kdbus/%I-user/bus;unix:path=/run/user/%I/bus
+,m4_dnl
+Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/%I/bus
+)m4_dnl
Slice=user-%i.slice