diff --git a/lib/preload.js b/lib/preload.js
index 831457b..659d463 100644
--- a/lib/preload.js
+++ b/lib/preload.js
@@ -1,7 +1,9 @@
 'use strict';
 
 // Modules
-const SynchronousWorker = require('@matteo.collina/worker');
+const {MessageChannel} = require('worker_threads'),
+	SynchronousWorker = require('@matteo.collina/worker'),
+	{isFunction} = require('is-it-type');
 
 // Imports
 const {createChannels, wrapError} = require('./utils.js'),
@@ -13,9 +15,12 @@ module.exports = function preload(loaderUrl, port, getBuiltin) {
 	const {listen, message, post} = createChannels(port, 'inner');
 	port.unref();
 
-	let loader;
+	let worker, loader;
 	try {
-		loader = importSync(loaderUrl);
+		worker = new SynchronousWorker();
+		const workerImport = worker.createRequire(__filename)('./import.js');
+		const promise = workerImport(loaderUrl);
+		loader = worker.runLoopUntilPromiseResolved(promise);
 	} catch (err) {
 		post(0, FAIL, INIT, wrapError(err));
 		return;
@@ -23,26 +28,30 @@ module.exports = function preload(loaderUrl, port, getBuiltin) {
 
 	const {resolve, load} = loader;
 
-	listen((channelId, hook, data) => (hook === RESOLVE ? resolve : load)(
-		...data,
-		(specifier, context) => message(channelId, NEXT, hook, [specifier, context])
-	));
+	listen((channelId, hook, data) => {
+		const promise = (hook === RESOLVE ? resolve : load)(
+			...data,
+			(specifier, context) => message(channelId, NEXT, hook, [specifier, context])
+		);
+
+		if (!promise || !isFunction(promise.then)) {
+			console.log('is not promise');
+			return promise;
+		}
+
+		const res = worker.runLoopUntilPromiseResolved(promise);
+		console.log('res:', res);
+		return res;
+	});
 
 	post(0, SUCCESS, INIT, {resolve: !!loader.resolve, load: !!loader.load});
 
 	if (loader.globalPreload) {
-		// TODO Proxy outer port
-		const preloadCode = loader.globalPreload();
-
-		// TODO Proxy inner port
+		const {port1, port2} = new MessageChannel();
+		const preloadCode = loader.globalPreload.call(undefined, {port: port1});
 		// eslint-disable-next-line no-new-func
-		new Function('getBuiltin', preloadCode)(getBuiltin);
+		new Function('getBuiltin', 'port', preloadCode)(getBuiltin, port2);
 	}
-};
 
-function importSync(url) {
-	const worker = new SynchronousWorker();
-	const workerImport = worker.createRequire(__filename)('./import.js');
-	const promise = workerImport(url);
-	return worker.runLoopUntilPromiseResolved(promise);
-}
+	// TODO Patch CommonJS loader
+};
diff --git a/lib/utils.js b/lib/utils.js
index ce5cbd2..13badc0 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -4,7 +4,7 @@
 const {isFunction} = require('is-it-type');
 
 // Imports
-const {INCOMING, SUCCESS, FAIL, ERROR, OTHER} = require('./constants.js');
+const {INCOMING, SUCCESS, FAIL, NEXT, ERROR, OTHER, RESOLVE, LOAD} = require('./constants.js');
 
 // Exports
 
@@ -16,17 +16,20 @@ function createChannels(port, logName) {
 
 	function listen(onIncoming) {
 		port.onmessage = ({data: {id, type, hook, data}}) => {
-			// TODO Remove console.log
-			// eslint-disable-next-line no-console
-			console.log(`${logName} received message:`, {id, type, hook, data});
+			logMessage(logName, 'received', id, type, hook, data);
 
 			if (type === INCOMING) {
-				onIncoming(id, hook, data).then(
-					res => post(id, SUCCESS, hook, res),
-					err => post(id, FAIL, hook, wrapError(err))
-				);
+				let res;
+				try {
+					res = onIncoming(id, hook, data);
+				} catch (err) {
+					post(id, FAIL, hook, wrapError(err));
+					return;
+				}
+				post(id, SUCCESS, hook, res);
 				return;
 			}
+
 			callbacks.get(id)(type, data);
 		};
 	}
@@ -69,9 +72,7 @@ function createChannels(port, logName) {
 	}
 
 	function post(id, type, hook, data) {
-		// TODO Remove console.log
-		// eslint-disable-next-line no-console
-		console.log(`${logName} sending message:`, {id, type, hook, data});
+		// debugMessage(logName, 'sending', id, type, hook, data);
 		port.postMessage({id, type, hook, data});
 	}
 
@@ -106,3 +107,12 @@ function unwrapError(errDef) {
 	Object.assign(err, errDef.props);
 	return err;
 }
+
+function logMessage(logName, action, id, type, hook, data) {
+	console.log(`${logName} ${action} message:`, { // eslint-disable-line no-console
+		id,
+		type: {[INCOMING]: 'INCOMING', [SUCCESS]: 'SUCCESS', [FAIL]: 'FAIL', [NEXT]: 'NEXT'}[type] || type,
+		hook: {[RESOLVE]: 'RESOLVE', [LOAD]: 'LOAD'}[hook] || hook,
+		data
+	});
+}