diff --git a/test/connector/active.spec.js b/test/connector/active.spec.js
index 4d8ed15..710d8ab 100644
--- a/test/connector/active.spec.js
+++ b/test/connector/active.spec.js
@@ -6,9 +6,10 @@ const net = require('net');
 const tls = require('tls');
 
 const ActiveConnector = require('../../src/connector/active');
-const findPort = require('../../src/helpers/find-port');
+const {getNextPortFactory} = require('../../src/helpers/find-port');
 
 describe('Connector - Active //', function () {
+  let getNextPort = getNextPortFactory(1024);
   let PORT;
   let active;
   let mockConnection = {};
@@ -21,7 +22,7 @@ describe('Connector - Active //', function () {
   beforeEach(done => {
     sandbox = sinon.sandbox.create();
 
-    findPort()
+    getNextPort()
     .then(port => {
       PORT = port;
       server = net.createServer()
diff --git a/test/connector/passive.spec.js b/test/connector/passive.spec.js
index 6f8db72..46c52a3 100644
--- a/test/connector/passive.spec.js
+++ b/test/connector/passive.spec.js
@@ -9,85 +9,114 @@ const bunyan = require('bunyan');
 const PassiveConnector = require('../../src/connector/passive');
 
 describe('Connector - Passive //', function () {
-  let passive;
   let mockConnection = {
     reply: () => Promise.resolve({}),
     close: () => Promise.resolve({}),
     encoding: 'utf8',
     log: bunyan.createLogger({name: 'passive-test'}),
-    commandSocket: {},
-    server: {options: {}, url: {}}
+    commandSocket: {
+      remoteAddress: '::ffff:127.0.0.1'
+    },
+    server: {
+      options: {
+        pasv_min: 1024
+      },
+      url: ''
+    }
   };
   let sandbox;
 
-  function shouldNotResolve() {
-    throw new Error('Should not resolve');
-  }
-
   before(() => {
-    passive = new PassiveConnector(mockConnection);
-  });
-  beforeEach(() => {
     sandbox = sinon.sandbox.create();
+  });
 
+  beforeEach(() => {
     sandbox.spy(mockConnection, 'reply');
     sandbox.spy(mockConnection, 'close');
-
-    mockConnection.commandSocket.remoteAddress = '::ffff:127.0.0.1';
-    mockConnection.server.options.pasv_range = '8000';
   });
   afterEach(() => {
     sandbox.restore();
   });
 
-  it('cannot wait for connection with no server', function () {
-    return passive.waitForConnection()
-    .then(shouldNotResolve)
+  it('cannot wait for connection with no server', function (done) {
+    let passive = new PassiveConnector(mockConnection);
+    passive.waitForConnection()
     .catch(err => {
       expect(err.name).to.equal('ConnectorError');
+      done();
     });
   });
 
-  it('no pasv range provided', function () {
-    delete mockConnection.server.options.pasv_range;
+  describe('setup', function () {
+    before(function () {
+      sandbox.stub(mockConnection.server.options, 'pasv_min').value(undefined);
+      sandbox.stub(mockConnection.server.options, 'pasv_max').value(undefined);
+    });
 
-    return passive.setupServer()
-    .then(shouldNotResolve)
-    .catch(err => {
-      expect(err.name).to.equal('ConnectorError');
+    it('no pasv range provided', function (done) {
+      let passive = new PassiveConnector(mockConnection);
+      passive.setupServer()
+      .catch(err => {
+        try {
+          expect(err.name).to.equal('ConnectorError');
+          done();
+        } catch (ex) {
+          done(ex);
+        }
+      });
     });
   });
 
-  it('has invalid pasv range', function () {
-    mockConnection.server.options.pasv_range = -1;
+  describe('setup', function () {
+    let connection;
+    before(function () {
+      sandbox.stub(mockConnection.server.options, 'pasv_min').value(-1);
+      sandbox.stub(mockConnection.server.options, 'pasv_max').value(-1);
 
-    return passive.setupServer()
-    .then(shouldNotResolve)
-    .catch(err => {
-      expect(err).to.be.instanceOf(RangeError);
+      connection = new PassiveConnector(mockConnection);
+    });
+
+    it('has invalid pasv range', function (done) {
+      connection.setupServer()
+      .catch(err => {
+        expect(err.name).to.equal('ConnectorError');
+        done();
+      });
     });
   });
 
   it('sets up a server', function () {
+    let passive = new PassiveConnector(mockConnection);
     return passive.setupServer()
     .then(() => {
       expect(passive.dataServer).to.exist;
     });
   });
 
-  it('destroys existing server, then sets up a server', function () {
-    const closeFnSpy = sandbox.spy(passive.dataServer, 'close');
+  describe('setup', function () {
+    let passive;
+    let closeFnSpy;
+    before(function () {
+      passive = new PassiveConnector(mockConnection);
+      return passive.setupServer()
+      .then(() => {
+        closeFnSpy = sandbox.spy(passive.dataServer, 'close');
+      });
+    });
 
-    return passive.setupServer()
-    .then(() => {
-      expect(closeFnSpy.callCount).to.equal(1);
-      expect(passive.dataServer).to.exist;
+    it('destroys existing server, then sets up a server', function () {
+      return passive.setupServer()
+      .then(() => {
+        expect(closeFnSpy.callCount).to.equal(1);
+        expect(passive.dataServer).to.exist;
+      });
     });
   });
 
   it('refuses connection with different remote address', function (done) {
-    mockConnection.commandSocket.remoteAddress = 'bad';
+    sandbox.stub(mockConnection.commandSocket, 'remoteAddress').value('bad');
 
+    let passive = new PassiveConnector(mockConnection);
     passive.setupServer()
     .then(() => {
       expect(passive.dataServer).to.exist;
@@ -106,6 +135,7 @@ describe('Connector - Passive //', function () {
   });
 
   it('accepts connection', function () {
+    let passive = new PassiveConnector(mockConnection);
     return passive.setupServer()
     .then(() => {
       expect(passive.dataServer).to.exist;
diff --git a/test/helpers/find-port.spec.js b/test/helpers/find-port.spec.js
index 567b5b8..e91ef1b 100644
--- a/test/helpers/find-port.spec.js
+++ b/test/helpers/find-port.spec.js
@@ -1,35 +1,52 @@
 /* eslint no-unused-expressions: 0 */
 const {expect} = require('chai');
-const {Server} = require('net');
+const net = require('net');
 const sinon = require('sinon');
 
-const findPort = require('../../src/helpers/find-port');
+const {getNextPortFactory} = require('../../src/helpers/find-port');
 
 describe('helpers // find-port', function () {
   let sandbox;
+  let getNextPort;
 
   beforeEach(() => {
     sandbox = sinon.sandbox.create();
 
-    sandbox.spy(Server.prototype, 'listen');
+    getNextPort = getNextPortFactory(1, 2);
   });
   afterEach(() => {
     sandbox.restore();
   });
 
   it('finds a port', () => {
-    return findPort(1)
+    sandbox.stub(net.Server.prototype, 'listen').callsFake(function (port) {
+      this.address = () => ({port});
+      setImmediate(() => this.emit('listening'));
+    });
+
+    return getNextPort()
     .then(port => {
-      expect(Server.prototype.listen.callCount).to.be.above(1);
-      expect(port).to.be.above(1);
+      expect(port).to.equal(1);
     });
   });
 
-  it('does not find a port', () => {
-    return findPort(1, 2)
-    .then(() => expect(1).to.equal(2)) // should not happen
-    .catch(err => {
-      expect(err).to.exist;
+  it('restarts count', () => {
+    sandbox.stub(net.Server.prototype, 'listen').callsFake(function (port) {
+      this.address = () => ({port});
+      setImmediate(() => this.emit('listening'));
+    });
+
+    return getNextPort()
+    .then(port => {
+      expect(port).to.equal(1);
+    })
+    .then(() => getNextPort())
+    .then(port => {
+      expect(port).to.equal(2);
+    })
+    .then(() => getNextPort())
+    .then(port => {
+      expect(port).to.equal(1);
     });
   });
 });
diff --git a/test/index.spec.js b/test/index.spec.js
index 496a10c..0d43d26 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -37,9 +37,10 @@ describe('Integration', function () {
   after(() => directoryPurge(clientDirectory));
 
   function startServer(url, options = {}) {
-    server = new FtpServer(url, _.assign({
+    server = new FtpServer(_.assign({
+      url,
       log,
-      pasv_range: 8881,
+      pasv_min: 8881,
       greeting: ['hello', 'world'],
       anonymous: true
     }, options));