diff --git a/package.json b/package.json
index 193c828d..b23f4a2c 100644
--- a/package.json
+++ b/package.json
@@ -58,7 +58,6 @@
     "merge-stream": "^1.0.1",
     "node-pty": "^0.4.1",
     "nodemon": "1.10.2",
-    "sleep": "^3.0.1",
     "sorcery": "^0.10.0",
     "tslint": "^4.0.2",
     "typescript": "~2.2.0",
diff --git a/src/test/escape-sequences-test.js b/src/test/escape-sequences-test.js
index 3053f0fb..5b1ccb71 100644
--- a/src/test/escape-sequences-test.js
+++ b/src/test/escape-sequences-test.js
@@ -2,7 +2,6 @@ var glob = require('glob');
 var fs = require('fs');
 var os = require('os');
 var pty = require('node-pty');
-var sleep = require('sleep');
 var Terminal = require('../xterm');
 
 if (os.platform() === 'win32') {
@@ -25,17 +24,18 @@ var primitive_pty = pty.native.open(COLS, ROWS);
 // we just pipe the data from slave to master as a child program would do
 // pty.js opens pipe fds with O_NONBLOCK
 // just wait 10ms instead of setting fds to blocking mode
-function pty_write_read(s) {
+function pty_write_read(s, cb) {
   fs.writeSync(primitive_pty.slave, s);
-  sleep.usleep(10000);
-  var b = Buffer(64000);
-  var bytes = fs.readSync(primitive_pty.master, b, 0, 64000);
-  return b.toString('utf8', 0, bytes);
+  setTimeout(() => {
+    var b = Buffer(64000);
+    var bytes = fs.readSync(primitive_pty.master, b, 0, 64000);
+    cb(b.toString('utf8', 0, bytes));
+  });
 }
 
 // make sure raw pty is at x=0 and has no pending data
-function pty_reset() {
-    pty_write_read('\r\n');
+function pty_reset(cb) {
+    pty_write_read('\r\n', cb);
 }
 
 /* debug helpers */
@@ -106,30 +106,33 @@ describe('xterm output comparison', function() {
       continue;
     }
     (function(filename) {
-      it(filename.split('/').slice(-1)[0], function () {
-        pty_reset();
-        var in_file = fs.readFileSync(filename, 'utf8');
-        var from_pty = pty_write_read(in_file);
-        // uncomment this to get log from terminal
-        //console.log = function(){};
+      it(filename.split('/').slice(-1)[0], done => {
+        pty_reset(() => {
+          var in_file = fs.readFileSync(filename, 'utf8');
+          pty_write_read(in_file, from_pty => {
+            // uncomment this to get log from terminal
+            //console.log = function(){};
 
-        // Perform a synchronous .write(data)
-        xterm.writeBuffer.push(from_pty);
-        xterm.innerWrite();
+            // Perform a synchronous .write(data)
+            xterm.writeBuffer.push(from_pty);
+            xterm.innerWrite();
 
-        var from_emulator = terminalToString(xterm);
-        console.log = CONSOLE_LOG;
-        var expected = fs.readFileSync(filename.split('.')[0] + '.text', 'utf8');
-        // Some of the tests have whitespace on the right of lines, we trim all the linex
-        // from xterm.js so ignore this for now at least.
-        var expectedRightTrimmed = expected.split('\n').map(function (l) {
-          return l.replace(/\s+$/, '');
-        }).join('\n');
-        if (from_emulator != expectedRightTrimmed) {
-          // uncomment to get noisy output
-          throw new Error(formatError(in_file, from_emulator, expected));
-        //   throw new Error('mismatch');
-        }
+            var from_emulator = terminalToString(xterm);
+            console.log = CONSOLE_LOG;
+            var expected = fs.readFileSync(filename.split('.')[0] + '.text', 'utf8');
+            // Some of the tests have whitespace on the right of lines, we trim all the linex
+            // from xterm.js so ignore this for now at least.
+            var expectedRightTrimmed = expected.split('\n').map(function (l) {
+              return l.replace(/\s+$/, '');
+            }).join('\n');
+            if (from_emulator != expectedRightTrimmed) {
+              // uncomment to get noisy output
+              throw new Error(formatError(in_file, from_emulator, expected));
+            //   throw new Error('mismatch');
+            }
+            done();
+          });
+        });
       });
     })(files[i]);
   }