diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index dea039163661..a687217eadd7 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -522,7 +522,7 @@ static int digi_set_modem_signals(struct usb_serial_port *port,
 		port_priv->dp_port_num, modem_signals);
 
 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
-	spin_lock(&port_priv->dp_port_lock);
+	spin_lock_nested(&port_priv->dp_port_lock, SINGLE_DEPTH_NESTING);
 
 	while (oob_priv->dp_write_urb_in_use) {
 		spin_unlock(&port_priv->dp_port_lock);