diff --git a/src/vhost_kern/vhost_binding.rs b/src/vhost_kern/vhost_binding.rs
index 57ae698..a2ae717 100644
--- a/src/vhost_kern/vhost_binding.rs
+++ b/src/vhost_kern/vhost_binding.rs
@@ -20,14 +20,14 @@ use std::os::raw;
 
 pub const VHOST: raw::c_uint = 0xaf;
 pub const VHOST_VRING_F_LOG: raw::c_uint = 0;
-pub const VHOST_ACCESS_RO: raw::c_uint = 1;
-pub const VHOST_ACCESS_WO: raw::c_uint = 2;
-pub const VHOST_ACCESS_RW: raw::c_uint = 3;
-pub const VHOST_IOTLB_MISS: raw::c_uint = 1;
-pub const VHOST_IOTLB_UPDATE: raw::c_uint = 2;
-pub const VHOST_IOTLB_INVALIDATE: raw::c_uint = 3;
-pub const VHOST_IOTLB_ACCESS_FAIL: raw::c_uint = 4;
-pub const VHOST_IOTLB_MSG: raw::c_uint = 1;
+pub const VHOST_ACCESS_RO: raw::c_uchar = 1;
+pub const VHOST_ACCESS_WO: raw::c_uchar = 2;
+pub const VHOST_ACCESS_RW: raw::c_uchar = 3;
+pub const VHOST_IOTLB_MISS: raw::c_uchar = 1;
+pub const VHOST_IOTLB_UPDATE: raw::c_uchar = 2;
+pub const VHOST_IOTLB_INVALIDATE: raw::c_uchar = 3;
+pub const VHOST_IOTLB_ACCESS_FAIL: raw::c_uchar = 4;
+pub const VHOST_IOTLB_MSG: raw::c_int = 1;
 pub const VHOST_PAGE_SIZE: raw::c_uint = 4096;
 pub const VHOST_VIRTIO: raw::c_uint = 175;
 pub const VHOST_VRING_LITTLE_ENDIAN: raw::c_uint = 0;