diff --git a/default.nix b/default.nix
index 42bea064..a72a78e7 100644
--- a/default.nix
+++ b/default.nix
@@ -15,7 +15,7 @@ let
       version = "0.1.0";
 
       src = ./src;
-      cargoSha256 = "1r8yjzixkknivawi286iyjjhaf5q8ll3a53q54dc9m9dhx20358b";
+      cargoSha256 = "1q5s193qcqjcvln7zphminfdg8by3dr05zq242965bmh0q46246v";
 
       nativeBuildInputs = [
         pkgs.gnumake
diff --git a/src/Cargo.lock b/src/Cargo.lock
index d42c75c5..1906931e 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -187,7 +187,7 @@ dependencies = [
 [[package]]
 name = "libasync"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#157439bc88cbb18bb40009428acf1fdee800e32e"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#a116142f6346193f272528e68c09af5eda771c0d"
 dependencies = [
  "embedded-hal",
  "libcortex_a9",
@@ -199,7 +199,7 @@ dependencies = [
 [[package]]
 name = "libboard_zynq"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#157439bc88cbb18bb40009428acf1fdee800e32e"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#a116142f6346193f272528e68c09af5eda771c0d"
 dependencies = [
  "bit_field",
  "embedded-hal",
@@ -233,7 +233,7 @@ dependencies = [
 [[package]]
 name = "libcortex_a9"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#157439bc88cbb18bb40009428acf1fdee800e32e"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#a116142f6346193f272528e68c09af5eda771c0d"
 dependencies = [
  "bit_field",
  "libregister",
@@ -249,7 +249,7 @@ checksum = "c7d73b3f436185384286bd8098d17ec07c9a7d2388a6599f824d8502b529702a"
 [[package]]
 name = "libregister"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#157439bc88cbb18bb40009428acf1fdee800e32e"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#a116142f6346193f272528e68c09af5eda771c0d"
 dependencies = [
  "bit_field",
  "vcell",
@@ -259,7 +259,7 @@ dependencies = [
 [[package]]
 name = "libsupport_zynq"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#157439bc88cbb18bb40009428acf1fdee800e32e"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#a116142f6346193f272528e68c09af5eda771c0d"
 dependencies = [
  "compiler_builtins",
  "libboard_zynq",
diff --git a/src/runtime/src/kernel/mod.rs b/src/runtime/src/kernel/mod.rs
index c3bb1fbe..39f73641 100644
--- a/src/runtime/src/kernel/mod.rs
+++ b/src/runtime/src/kernel/mod.rs
@@ -1,5 +1,5 @@
 use core::ptr;
-use alloc::{vec::Vec, string::String};
+use alloc::{vec::Vec, string::String, sync::Arc};
 
 use libcortex_a9::{mutex::Mutex, sync_channel, semaphore::Semaphore};
 use crate::eh_artiq;
@@ -32,7 +32,7 @@ pub enum Message {
     StartRequest,
     KernelFinished,
     KernelException(&'static eh_artiq::Exception<'static>, &'static [usize]),
-    RpcSend { is_async: bool, data: Vec<u8> },
+    RpcSend { is_async: bool, data: Arc<Vec<u8>> },
     RpcRecvRequest(*mut ()),
     RpcRecvReply(Result<usize, RPCException>),
 
diff --git a/src/runtime/src/kernel/rpc.rs b/src/runtime/src/kernel/rpc.rs
index de0dff8c..fd15afa3 100644
--- a/src/runtime/src/kernel/rpc.rs
+++ b/src/runtime/src/kernel/rpc.rs
@@ -1,6 +1,6 @@
 //! Kernel-side RPC API
 
-use alloc::vec::Vec;
+use alloc::{vec::Vec, sync::Arc};
 use cslice::{CSlice, AsCSlice};
 
 use crate::eh_artiq;
@@ -14,7 +14,7 @@ fn rpc_send_common(is_async: bool, service: u32, tag: &CSlice<u8>, data: *const
     let core1_tx = unsafe { KERNEL_CHANNEL_1TO0.as_mut().unwrap() };
     let mut buffer = Vec::<u8>::new();
     send_args(&mut buffer, service, tag.as_ref(), data).expect("RPC encoding failed");
-    core1_tx.send(Message::RpcSend { is_async, data: buffer });
+    core1_tx.send(Message::RpcSend { is_async, data: Arc::new(buffer) });
 }
 
 pub extern fn rpc_send(service: u32, tag: &CSlice<u8>, data: *const *const ()) {