diff --git a/cli/src/main.rs b/cli/src/main.rs
index 41bedece..60a3cda7 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -1,7 +1,7 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
-use andromeda_core::{Runtime, RuntimeConfig};
+use andromeda_core::{HostData, Runtime, RuntimeConfig};
 use andromeda_runtime::{
     recommended_builtins, recommended_eventloop_handler, recommended_extensions,
 };
@@ -49,14 +49,20 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             no_strict,
             paths,
         } => {
-            let runtime = Runtime::new(RuntimeConfig {
-                no_strict,
-                paths,
-                verbose,
-                extensions: recommended_extensions(),
-                builtins: recommended_builtins(),
-                eventloop_handler: recommended_eventloop_handler,
-            });
+            let (macro_task_tx, macro_task_rx) = std::sync::mpsc::channel();
+            let host_data = HostData::new(macro_task_tx);
+            let runtime = Runtime::new(
+                RuntimeConfig {
+                    no_strict,
+                    paths,
+                    verbose,
+                    extensions: recommended_extensions(),
+                    builtins: recommended_builtins(),
+                    eventloop_handler: recommended_eventloop_handler,
+                    macro_task_rx,
+                },
+                host_data,
+            );
             let mut runtime_output = runtime.run();
 
             match runtime_output.result {
diff --git a/core/src/host_data.rs b/core/src/host_data.rs
index 37661af6..97f5c288 100644
--- a/core/src/host_data.rs
+++ b/core/src/host_data.rs
@@ -5,7 +5,7 @@ use std::{
     sync::{
         Arc,
         atomic::{AtomicU32, Ordering},
-        mpsc::{Receiver, Sender},
+        mpsc::Sender,
     },
 };
 
@@ -33,18 +33,14 @@ pub struct HostData<UserMacroTask> {
 }
 
 impl<UserMacroTask> HostData<UserMacroTask> {
-    pub fn new() -> (Self, Receiver<MacroTask<UserMacroTask>>) {
-        let (macro_task_tx, rx) = std::sync::mpsc::channel();
-        (
-            Self {
-                storage: RefCell::new(AnyMap::new()),
-                macro_task_tx,
-                macro_task_count: Arc::new(AtomicU32::new(0)),
-                tasks: RefCell::default(),
-                task_count: Arc::default(),
-            },
-            rx,
-        )
+    pub fn new(macro_task_tx: Sender<MacroTask<UserMacroTask>>) -> Self {
+        Self {
+            storage: RefCell::new(AnyMap::new()),
+            macro_task_tx,
+            macro_task_count: Arc::new(AtomicU32::new(0)),
+            tasks: RefCell::default(),
+            task_count: Arc::default(),
+        }
     }
 
     /// Get an owned senderto the macro tasks event loop.
diff --git a/core/src/runtime.rs b/core/src/runtime.rs
index ed1087f6..998434a8 100644
--- a/core/src/runtime.rs
+++ b/core/src/runtime.rs
@@ -79,6 +79,8 @@ pub struct RuntimeConfig<UserMacroTask: 'static> {
     pub builtins: Vec<&'static str>,
     /// User event loop handler.
     pub eventloop_handler: EventLoopHandler<UserMacroTask>,
+    /// Macro tasks eventloop receiver.
+    pub macro_task_rx: Receiver<MacroTask<UserMacroTask>>,
 }
 
 pub struct Runtime<UserMacroTask: 'static> {
@@ -86,13 +88,14 @@ pub struct Runtime<UserMacroTask: 'static> {
     pub agent: GcAgent,
     pub realm_root: RealmRoot,
     pub host_hooks: &'static RuntimeHostHooks<UserMacroTask>,
-    pub macro_task_rx: Receiver<MacroTask<UserMacroTask>>,
 }
 
 impl<UserMacroTask> Runtime<UserMacroTask> {
     /// Create a new [Runtime] given a [RuntimeConfig]. Use [Runtime::run] to run it.
-    pub fn new(mut config: RuntimeConfig<UserMacroTask>) -> Self {
-        let (host_data, macro_task_rx) = HostData::new();
+    pub fn new(
+        mut config: RuntimeConfig<UserMacroTask>,
+        host_data: HostData<UserMacroTask>,
+    ) -> Self {
         let host_hooks = RuntimeHostHooks::new(host_data);
 
         let host_hooks: &RuntimeHostHooks<UserMacroTask> = &*Box::leak(Box::new(host_hooks));
@@ -125,7 +128,6 @@ impl<UserMacroTask> Runtime<UserMacroTask> {
             agent,
             realm_root,
             host_hooks,
-            macro_task_rx,
         }
     }
 
@@ -204,7 +206,7 @@ impl<UserMacroTask> Runtime<UserMacroTask> {
 
     // Listen for pending macro tasks and resolve one by one
     pub fn handle_macro_task(&mut self) {
-        match self.macro_task_rx.recv() {
+        match self.config.macro_task_rx.recv() {
             Ok(MacroTask::ResolvePromise(root_value)) => {
                 self.agent.run_in_realm(&self.realm_root, |agent, gc| {
                     let value = root_value.take(agent);