diff --git a/benchmarks/middleware.js b/benchmarks/middleware.js
index e6bc6a7..bfa854f 100644
--- a/benchmarks/middleware.js
+++ b/benchmarks/middleware.js
@@ -13,7 +13,7 @@ while (n--) {
   app.use((ctx, next) => next());
 }
 
-const body = new Buffer('Hello World');
+const body = Buffer.from('Hello World');
 
 app.use((ctx, next) => next().then(() => ctx.body = body));
 
diff --git a/test/application/respond.js b/test/application/respond.js
index a2a6861..b8f9211 100644
--- a/test/application/respond.js
+++ b/test/application/respond.js
@@ -124,7 +124,7 @@ describe('app.respond', () => {
       const app = new Koa();
 
       app.use(ctx => {
-        ctx.body = new Buffer('hello world');
+        ctx.body = Buffer.from('hello world');
       });
 
       const server = app.listen();
@@ -513,7 +513,7 @@ describe('app.respond', () => {
       const app = new Koa();
 
       app.use(ctx => {
-        ctx.body = new Buffer('Hello');
+        ctx.body = Buffer.from('Hello');
       });
 
       const server = app.listen();
@@ -521,7 +521,7 @@ describe('app.respond', () => {
       return request(server)
         .get('/')
         .expect(200)
-        .expect(new Buffer('Hello'));
+        .expect(Buffer.from('Hello'));
     });
   });
 
diff --git a/test/response/body.js b/test/response/body.js
index 29254e3..d4fd2df 100644
--- a/test/response/body.js
+++ b/test/response/body.js
@@ -10,7 +10,7 @@ describe('res.body=', () => {
     it('should not override', () => {
       const res = response();
       res.type = 'png';
-      res.body = new Buffer('something');
+      res.body = Buffer.from('something');
       assert('image/png' == res.header['content-type']);
     });
 
@@ -113,13 +113,13 @@ describe('res.body=', () => {
   describe('when a buffer is given', () => {
     it('should default to an octet stream', () => {
       const res = response();
-      res.body = new Buffer('hey');
+      res.body = Buffer.from('hey');
       assert('application/octet-stream' == res.header['content-type']);
     });
 
     it('should set length', () => {
       const res = response();
-      res.body = new Buffer('Tobi');
+      res.body = Buffer.from('Tobi');
       assert('4' == res.header['content-length']);
     });
   });
diff --git a/test/response/length.js b/test/response/length.js
index aaf538f..f473b2a 100644
--- a/test/response/length.js
+++ b/test/response/length.js
@@ -37,11 +37,11 @@ describe('res.length', () => {
         res.body = 'foo';
         res.length.should.equal(3);
 
-        res.body = new Buffer('foo bar');
+        res.body = Buffer.from('foo bar');
         res.remove('Content-Length');
         res.length.should.equal(7);
 
-        res.body = new Buffer('foo bar');
+        res.body = Buffer.from('foo bar');
         res.length.should.equal(7);
 
         res.body = { hello: 'world' };
diff --git a/test/response/writeable.js b/test/response/writeable.js
index c1816e6..ff1f89d 100644
--- a/test/response/writeable.js
+++ b/test/response/writeable.js
@@ -41,7 +41,7 @@ describe('res.writable', () => {
   describe('when socket closed before response sent', () => {
     function requsetClosed(server){
       const port = server.address().port;
-      const buf = new Buffer('GET / HTTP/1.1\r\nHost: localhost:' + port + '\r\nConnection: keep-alive\r\n\r\n');
+      const buf = Buffer.from('GET / HTTP/1.1\r\nHost: localhost:' + port + '\r\nConnection: keep-alive\r\n\r\n');
       const client = net.connect(port);
       setImmediate(() => {
         client.write(buf);
@@ -66,7 +66,7 @@ describe('res.writable', () => {
   describe('when response finished', () => {
     function request(server){
       const port = server.address().port;
-      const buf = new Buffer('GET / HTTP/1.1\r\nHost: localhost:' + port + '\r\nConnection: keep-alive\r\n\r\n');
+      const buf = Buffer.from('GET / HTTP/1.1\r\nHost: localhost:' + port + '\r\nConnection: keep-alive\r\n\r\n');
       const client = net.connect(port);
       setImmediate(() => {
         client.write(buf);