diff --git a/lib/index.js b/lib/index.js
index 4d76472..8b3648a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -120,10 +120,9 @@ function get_asset_handler(opts) {
 	return (req, res, next) => {
 		if (!opts.filter(req.pathname)) return next();
 
-		res.set({
-			'Content-Type': opts.type,
-			'Cache-Control': opts.cache
-		});
+		res.setHeader('Content-Type', opts.type);
+		res.setHeader('Cache-Control', opts.cache);
+
 		res.end(opts.fn(req.pathname));
 	};
 }
@@ -139,7 +138,7 @@ function get_route_handler(fn) {
 		if (route.type === 'page') {
 			// preload main.js and current route
 			// TODO detect other stuff we can preload? images, CSS, fonts?
-			res.set('Link', `<${client.main_file}>;rel="preload";as="script", <${client.routes[route.id]}>;rel="preload";as="script"`);
+			res.setHeader('Link', `<${client.main_file}>;rel="preload";as="script", <${client.routes[route.id]}>;rel="preload";as="script"`);
 
 			const data = { params: req.params, query: req.query };
 
@@ -198,9 +197,7 @@ function get_route_handler(fn) {
 		const url = req.pathname;
 
 		// whatever happens, we're going to serve some HTML
-		res.set({
-			'Content-Type': 'text/html'
-		});
+		res.setHeader('Content-Type', 'text/html');
 
 		resolved
 			.then(() => {
@@ -212,7 +209,7 @@ function get_route_handler(fn) {
 				next();
 			})
 			.catch(err => {
-				res.status(500);
+				res.statusCode = 500;
 				res.end(templates.render(500, {
 					title: (err && err.name) || 'Internal server error',
 					url,
@@ -227,7 +224,7 @@ function get_not_found_handler(fn) {
 	return function handle_not_found(req, res) {
 		const asset_cache = fn();
 
-		res.status(404);
+		res.statusCode = 404;
 		res.end(templates.render(404, {
 			title: 'Not found',
 			status: 404,
diff --git a/test/common/test.js b/test/common/test.js
index f044bda..250f596 100644
--- a/test/common/test.js
+++ b/test/common/test.js
@@ -41,7 +41,11 @@ function run(env) {
 				};
 
 				const res = {
-					set: (headers, value) => {
+					setHeader(header, value) {
+						result.headers[header] = value;
+					},
+
+					set(headers, value) {
 						if (typeof headers === 'string') {
 							return res.set({ [headers]: value });
 						}
@@ -49,15 +53,15 @@ function run(env) {
 						Object.assign(result.headers, headers);
 					},
 
-					status: code => {
+					status(code) {
 						result.status = code;
 					},
 
-					write: data => {
+					write(data) {
 						result.body += data;
 					},
 
-					end: data => {
+					end(data) {
 						result.body += data;
 						fulfil(result);
 					}