diff --git a/sys/dev/uart/uart_bus.h b/sys/dev/uart/uart_bus.h
index e78d7697979a..e42c4f5bfef5 100644
--- a/sys/dev/uart/uart_bus.h
+++ b/sys/dev/uart/uart_bus.h
@@ -150,6 +150,7 @@ void uart_sched_softih(struct uart_softc *, uint32_t);
 
 int uart_tty_attach(struct uart_softc *);
 int uart_tty_detach(struct uart_softc *);
+struct mtx *uart_tty_getlock(struct uart_softc *);
 void uart_tty_intr(void *arg);
 
 /*
diff --git a/sys/dev/uart/uart_core.c b/sys/dev/uart/uart_core.c
index 191244a2ae02..a2895b1b1a6a 100644
--- a/sys/dev/uart/uart_core.c
+++ b/sys/dev/uart/uart_core.c
@@ -511,9 +511,6 @@ uart_bus_attach(device_t dev)
 		    sc->sc_sysdev->stopbits);
 	}
 
-	sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
-	pps_init(&sc->sc_pps);
-
 	sc->sc_leaving = 0;
 	sc->sc_testintr = 1;
 	filt = uart_intr(sc);
@@ -568,10 +565,17 @@ uart_bus_attach(device_t dev)
 		printf("\n");
 	}
 
-	error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
-	    ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
-	if (error)
-		goto fail;
+	if (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL) {
+		if ((error = sc->sc_sysdev->attach(sc)) != 0)
+			goto fail;
+	} else {
+		if ((error = uart_tty_attach(sc)) != 0)
+			goto fail;
+		sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
+		sc->sc_pps.driver_mtx = uart_tty_getlock(sc);
+		sc->sc_pps.driver_abi = PPS_ABI_VERSION;
+		pps_init_abi(&sc->sc_pps);
+	}
 
 	if (sc->sc_sysdev != NULL)
 		sc->sc_sysdev->hwmtx = sc->sc_hwmtx;
diff --git a/sys/dev/uart/uart_tty.c b/sys/dev/uart/uart_tty.c
index c31b5429ae9a..ada49277c187 100644
--- a/sys/dev/uart/uart_tty.c
+++ b/sys/dev/uart/uart_tty.c
@@ -404,3 +404,13 @@ uart_tty_detach(struct uart_softc *sc)
 
 	return (0);
 }
+
+struct mtx *
+uart_tty_getlock(struct uart_softc *sc)
+{
+
+	if (sc->sc_u.u_tty.tp != NULL)
+		return (tty_getlock(sc->sc_u.u_tty.tp));
+	else
+		return (NULL);
+}