diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index efe3e3b85769..dafedc33928d 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -2931,9 +2931,8 @@ static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
 
 		t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
 		t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
-		memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
-		       ARRAY_SIZE(desc->CompatibleID) +
-		       ARRAY_SIZE(desc->SubCompatibleID));
+		memcpy(t->os_desc->ext_compat_id, &desc->IDs,
+		       sizeof_field(struct usb_ext_compat_desc, IDs));
 		length = sizeof(*desc);
 	}
 		break;
diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index d77ee6b65328..078098e73fd3 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -73,8 +73,10 @@ struct usb_os_desc_header {
 struct usb_ext_compat_desc {
 	__u8	bFirstInterfaceNumber;
 	__u8	Reserved1;
-	__u8	CompatibleID[8];
-	__u8	SubCompatibleID[8];
+	__struct_group(/* no tag */, IDs, /* no attrs */,
+		__u8	CompatibleID[8];
+		__u8	SubCompatibleID[8];
+	);
 	__u8	Reserved2[6];
 };