diff --git a/src/runtime/src/comms.rs b/src/runtime/src/comms.rs
index bb0ac50..e88beff 100644
--- a/src/runtime/src/comms.rs
+++ b/src/runtime/src/comms.rs
@@ -488,14 +488,14 @@ async fn handle_run_kernel(
                             kernel::Message::RpcRecvRequest(slot) => slot,
                             other => panic!("expected root value slot from core1, not {:?}", other),
                         };
-                        let remaining_tags = rpc::recv_return(&mut reader, &current_tags, slot, &mut |size| {
+                        let remaining_tags = rpc::recv_return(&mut reader, &current_tags, slot, &mut |size| -> Result<*mut ()> {
                             if size == 0 {
-                                0 as *mut ()
+                                Ok(0 as *mut ())
                             } else {
                                 let mut control = control.borrow_mut();
                                 control.tx.send(kernel::Message::RpcRecvReply(Ok(size)));
                                 match control.rx.recv() {
-                                    kernel::Message::RpcRecvRequest(slot) => slot,
+                                    kernel::Message::RpcRecvRequest(slot) => Ok(slot),
                                     other => {
                                         panic!("expected nested value slot from kernel CPU, not {:?}", other)
                                     }
diff --git a/src/runtime/src/rtio_mgt.rs b/src/runtime/src/rtio_mgt.rs
index f62fe75..b4253cc 100644
--- a/src/runtime/src/rtio_mgt.rs
+++ b/src/runtime/src/rtio_mgt.rs
@@ -55,8 +55,8 @@ pub mod drtio {
         }
     }
 
-    impl From<DrtioError> for Error {
-        fn from(_error: DrtioError) -> Self {
+    impl<T> From<DrtioError<T>> for Error {
+        fn from(_error: DrtioError<T>) -> Self {
             Error::AuxError
         }
     }
diff --git a/src/satman/src/subkernel.rs b/src/satman/src/subkernel.rs
index a14f939..8da8199 100644
--- a/src/satman/src/subkernel.rs
+++ b/src/satman/src/subkernel.rs
@@ -9,7 +9,7 @@ use core::{slice, str};
 use cslice::AsCSlice;
 use dma::{Error as DmaError, Manager as DmaManager};
 use io::{Cursor, Error as IoError, ProtoWrite, Write};
-use ksupport::{eh_artiq, kernel, rpc};
+use ksupport::{eh_artiq, kernel, rpc, rtio};
 use libboard_artiq::{
     drtio_routing::RoutingTable,
     drtioaux,