diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c
index ad3a7bc31d6f..af946d12e764 100644
--- a/drivers/tty/serial/8250/8250_platform.c
+++ b/drivers/tty/serial/8250/8250_platform.c
@@ -284,6 +284,7 @@ static struct platform_driver serial8250_isa_driver = {
 	.driver		= {
 		.name	= "serial8250",
 		.acpi_match_table = acpi_platform_serial_table,
+		.probe_type = PROBE_FORCE_SYNCHRONOUS,
 	},
 };
 
diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 7a837fdf9df1..3f41a9d6cb27 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -521,6 +521,7 @@ static struct pnp_driver serial_pnp_driver = {
 	.remove		= serial_pnp_remove,
 	.driver         = {
 		.pm     = pm_sleep_ptr(&serial_pnp_pm_ops),
+		.probe_type = PROBE_FORCE_SYNCHRONOUS,
 	},
 	.id_table	= pnp_dev_table,
 };