diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h
index 9158c61f6851..4141afb101bb 100644
--- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h
+++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h
@@ -106,7 +106,7 @@ int libcfs_deregister_ioctl(struct libcfs_ioctl_handler *hand);
 int libcfs_ioctl_getdata(struct libcfs_ioctl_hdr **hdr_pp,
 			 const struct libcfs_ioctl_hdr __user *uparam);
 int libcfs_ioctl_data_adjust(struct libcfs_ioctl_data *data);
-int libcfs_ioctl(unsigned long cmd, void *arg);
+int libcfs_ioctl(unsigned long cmd, void __user *arg);
 
 /* container_of depends on "likely" which is defined in libcfs_private.h */
 static inline void *__container_of(void *ptr, unsigned long shift)