diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 16d682f..c904913 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -347,6 +347,9 @@
 extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
 					unsigned int ch);
 extern int usb_serial_handle_break(struct usb_serial_port *port);
+extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
+					 struct tty_struct *tty,
+					 unsigned int status);
 
 
 extern int usb_serial_bus_register(struct usb_serial_driver *device);