diff --git a/sys/dev/uart/uart_bus.h b/sys/dev/uart/uart_bus.h
index 322e9a8..f40ad9a 100644
--- a/sys/dev/uart/uart_bus.h
+++ b/sys/dev/uart/uart_bus.h
@@ -70,6 +70,7 @@ struct uart_class {
 	struct uart_ops *uc_ops;	/* Low-level console operations. */
 	u_int	uc_range;		/* Bus space address range. */
 	u_int	uc_rclk;		/* Default rclk for this device. */
+	u_int	uc_regshft;		/* Default regshift for this device. */
 };
 
 struct uart_softc {
diff --git a/sys/dev/uart/uart_bus_fdt.c b/sys/dev/uart/uart_bus_fdt.c
index 3c68d95..b19d2dd 100644
--- a/sys/dev/uart/uart_bus_fdt.c
+++ b/sys/dev/uart/uart_bus_fdt.c
@@ -92,7 +92,7 @@ uart_fdt_get_shift(phandle_t node, pcell_t *cell)
 	pcell_t shift;
 
 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
-		shift = 0;
+		return (-1);
 	*cell = fdt32_to_cpu(shift);
 	return (0);
 }
@@ -132,7 +132,8 @@ uart_fdt_probe(device_t dev)
 
 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
 		return (err);
-	uart_fdt_get_shift(node, &shift);
+	if (uart_fdt_get_shift(node, &shift) < 0)
+		shift = sc->sc_class->uc_regshft;
 
 	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
 }
diff --git a/sys/dev/uart/uart_cpu_fdt.c b/sys/dev/uart/uart_cpu_fdt.c
index 8dfdb3c..541d219 100644
--- a/sys/dev/uart/uart_cpu_fdt.c
+++ b/sys/dev/uart/uart_cpu_fdt.c
@@ -84,10 +84,12 @@ uart_fdt_get_shift(phandle_t node, pcell_t *cell)
 {
 	pcell_t shift;
 
-	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
-		shift = 0;
-	*cell = fdt32_to_cpu(shift);
-	return (0);
+	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) > 0) {
+		*cell = fdt32_to_cpu(shift);
+		return (0);
+	}
+
+	return (-1);
 }
 
 int
@@ -193,7 +195,7 @@ uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 	/*
 	 * Retrieve serial attributes.
 	 */
-	uart_fdt_get_shift(node, &shift);
+
 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
 		br = 0;
 	else
@@ -217,6 +219,9 @@ uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 		rclk = 0;
 	}
 
+	if (uart_fdt_get_shift(node, &shift) < 0)
+		shift = class->uc_regshft;
+
 	/*
 	 * Finalize configuration.
 	 */