diff --git a/lib/net.js b/lib/net.js
index 5129a596421e1c..77823b9f8d9fc9 100644
--- a/lib/net.js
+++ b/lib/net.js
@@ -825,8 +825,19 @@ protoGetter('bytesWritten', function bytesWritten() {
       bytes += Buffer.byteLength(el.chunk, el.encoding);
   });
 
-  if (data) {
-    if (data instanceof Buffer)
+  if (Array.isArray(data)) {
+    // was a writev, iterate over chunks to get total length
+    for (var i = 0; i < data.length; i++) {
+      const chunk = data[i];
+
+      if (data.allBuffers || chunk instanceof Buffer)
+        bytes += chunk.length;
+      else
+        bytes += Buffer.byteLength(chunk.chunk, chunk.encoding);
+    }
+  } else if (data) {
+    // Writes are either a string or a Buffer.
+    if (typeof data !== 'string')
       bytes += data.length;
     else
       bytes += Buffer.byteLength(data, encoding);
diff --git a/test/parallel/test-net-socket-byteswritten.js b/test/parallel/test-net-socket-byteswritten.js
new file mode 100644
index 00000000000000..6f3ce8a3c6c8d1
--- /dev/null
+++ b/test/parallel/test-net-socket-byteswritten.js
@@ -0,0 +1,35 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+
+const server = net.createServer(function(socket) {
+  socket.end();
+});
+
+server.listen(0, common.mustCall(function() {
+  const socket = net.connect(server.address().port);
+
+  // Cork the socket, then write twice; this should cause a writev, which
+  // previously caused an err in the bytesWritten count.
+  socket.cork();
+
+  socket.write('one');
+  socket.write(new Buffer('twø', 'utf8'));
+
+  socket.uncork();
+
+  // one = 3 bytes, twø = 4 bytes
+  assert.strictEqual(socket.bytesWritten, 3 + 4);
+
+  socket.on('connect', common.mustCall(function() {
+    assert.strictEqual(socket.bytesWritten, 3 + 4);
+  }));
+
+  socket.on('end', common.mustCall(function() {
+    assert.strictEqual(socket.bytesWritten, 3 + 4);
+
+    server.close();
+  }));
+}));