diff --git a/drivers/usb/serial/keyspan.h b/drivers/usb/serial/keyspan.h
index 8a0d17401529..74ce8bca3e66 100644
--- a/drivers/usb/serial/keyspan.h
+++ b/drivers/usb/serial/keyspan.h
@@ -637,6 +637,7 @@ static struct usb_serial_driver keyspan_pre_device = {
 	.description		= "Keyspan - (without firmware)",
 	.id_table		= keyspan_pre_ids,
 	.num_interrupt_in	= NUM_DONT_CARE,
+	.num_interrupt_out	= NUM_DONT_CARE,
 	.num_bulk_in		= NUM_DONT_CARE,
 	.num_bulk_out		= NUM_DONT_CARE,
 	.num_ports		= 1,
@@ -651,6 +652,7 @@ static struct usb_serial_driver keyspan_1port_device = {
 	.description		= "Keyspan 1 port adapter",
 	.id_table		= keyspan_1port_ids,
 	.num_interrupt_in	= NUM_DONT_CARE,
+	.num_interrupt_out	= NUM_DONT_CARE,
 	.num_bulk_in		= NUM_DONT_CARE,
 	.num_bulk_out		= NUM_DONT_CARE,
 	.num_ports		= 1,
@@ -678,6 +680,7 @@ static struct usb_serial_driver keyspan_2port_device = {
 	.description		= "Keyspan 2 port adapter",
 	.id_table		= keyspan_2port_ids,
 	.num_interrupt_in	= NUM_DONT_CARE,
+	.num_interrupt_out	= NUM_DONT_CARE,
 	.num_bulk_in		= NUM_DONT_CARE,
 	.num_bulk_out		= NUM_DONT_CARE,
 	.num_ports		= 2,
@@ -705,6 +708,7 @@ static struct usb_serial_driver keyspan_4port_device = {
 	.description		= "Keyspan 4 port adapter",
 	.id_table		= keyspan_4port_ids,
 	.num_interrupt_in	= NUM_DONT_CARE,
+	.num_interrupt_out	= NUM_DONT_CARE,
 	.num_bulk_in		= NUM_DONT_CARE,
 	.num_bulk_out		= NUM_DONT_CARE,
 	.num_ports		= 4,