diff --git a/src/io/sendmsg.rs b/src/io/sendmsg.rs
index 5b02288c..1b355135 100644
--- a/src/io/sendmsg.rs
+++ b/src/io/sendmsg.rs
@@ -55,11 +55,11 @@ impl<T: BoundedBuf, U: BoundedBuf> Op<SendMsg<T, U>> {
         match msg_control {
             Some(ref _msg_control) => {
                 msghdr.msg_control = _msg_control.stable_ptr() as *mut _;
-                msghdr.msg_controllen = _msg_control.bytes_init();
+                msghdr.msg_controllen = _msg_control.bytes_init() as _;
             }
             None => {
                 msghdr.msg_control = std::ptr::null_mut();
-                msghdr.msg_controllen = 0_usize;
+                msghdr.msg_controllen = 0_usize as _;
             }
         }
 
diff --git a/src/io/sendmsg_zc.rs b/src/io/sendmsg_zc.rs
index e7da9fe5..724a4ba4 100644
--- a/src/io/sendmsg_zc.rs
+++ b/src/io/sendmsg_zc.rs
@@ -62,11 +62,11 @@ impl<T: BoundedBuf, U: BoundedBuf> Op<SendMsgZc<T, U>, MultiCQEFuture> {
         match msg_control {
             Some(ref _msg_control) => {
                 msghdr.msg_control = _msg_control.stable_ptr() as *mut _;
-                msghdr.msg_controllen = _msg_control.bytes_init();
+                msghdr.msg_controllen = _msg_control.bytes_init() as _;
             }
             None => {
                 msghdr.msg_control = std::ptr::null_mut();
-                msghdr.msg_controllen = 0_usize;
+                msghdr.msg_controllen = 0_usize as _;
             }
         }