diff --git a/drivers/usb/gadget/u_serial.c b/drivers/usb/gadget/u_serial.c
index adf8260..16bdf77 100644
--- a/drivers/usb/gadget/u_serial.c
+++ b/drivers/usb/gadget/u_serial.c
@@ -23,6 +23,7 @@
 #include <linux/delay.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
+#include <linux/slab.h>
 
 #include "u_serial.h"