diff --git a/drivers/usb/gadget/u_f.c b/drivers/usb/gadget/u_f.c
index 4bc7eea8bfc8..6811761fec64 100644
--- a/drivers/usb/gadget/u_f.c
+++ b/drivers/usb/gadget/u_f.c
@@ -13,7 +13,7 @@
 
 #include "u_f.h"
 
-struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len)
+struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len)
 {
 	struct usb_request      *req;
 
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 4247cc098a89..21b75710c4a4 100644
--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -48,7 +48,7 @@ struct usb_ep;
 struct usb_request;
 
 /* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */
-struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len);
+struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len);
 static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 {
 	kfree(req->buf);