diff --git a/package.json b/package.json
index 319e4b6..8fd5484 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,6 @@
   "homepage": "https://github.com/nicdex/eventstore-node#readme",
   "dependencies": {
     "protobufjs": "^5.0.1",
-    "uuid": "^2.0.1",
-    "when": "^3.7.7"
+    "uuid": "^2.0.1"
   }
 }
diff --git a/src/core/staticEndpointDiscoverer.js b/src/core/staticEndpointDiscoverer.js
index cb1a551..5f4f05c 100644
--- a/src/core/staticEndpointDiscoverer.js
+++ b/src/core/staticEndpointDiscoverer.js
@@ -1,5 +1,3 @@
-var when = require('when');
-
 function StaticEndpointDiscoverer(tcpEndPoint, useSsl) {
   this._nodeEndpoints = {
     tcpEndPoint: useSsl ? null : tcpEndPoint,
@@ -8,7 +6,7 @@ function StaticEndpointDiscoverer(tcpEndPoint, useSsl) {
 }
 
 StaticEndpointDiscoverer.prototype.discover = function(failedTcpEndpoint) {
-  return when(this._nodeEndpoints);
+  return Promise.resolve(this._nodeEndpoints);
 };
 
 module.exports = StaticEndpointDiscoverer;
\ No newline at end of file
diff --git a/src/eventStoreAllCatchUpSubscription.js b/src/eventStoreAllCatchUpSubscription.js
index 6f413c5..50dd85f 100644
--- a/src/eventStoreAllCatchUpSubscription.js
+++ b/src/eventStoreAllCatchUpSubscription.js
@@ -1,5 +1,4 @@
 var util = require('util');
-var when = require('when');
 
 var EventStoreCatchUpSubscription = require('./eventStoreCatchUpSubscription');
 var results = require('./results');
@@ -26,10 +25,10 @@ EventStoreAllCatchUpSubscription.prototype._readEventsTill = function(
 
   function processEvents(events, index) {
     index = index || 0;
-    if (index >= events.length) return when();
+    if (index >= events.length) return Promise.resolve();
     if (events[index].originalPosition === null) throw new Error("Subscription event came up with no OriginalPosition.");
 
-    return when.promise(function(resolve, reject) {
+    return new Promise(function(resolve, reject) {
           self._tryProcess(events[index]);
           resolve();
         })
@@ -48,8 +47,8 @@ EventStoreAllCatchUpSubscription.prototype._readEventsTill = function(
                     ? slice.isEndOfStream
                     : slice.nextPosition.compareTo(new results.Position(lastCommitPosition, lastCommitPosition)) >= 0;
                 if (!done && slice.isEndOfStream)
-                    return when(done).delay(10);
-                return when(done);
+                    return Promise.resolve(done).delay(10);
+                return Promise.resolve(done);
               });
         })
         .then(function(done) {
diff --git a/src/eventStoreCatchUpSubscription.js b/src/eventStoreCatchUpSubscription.js
index bfcbc90..61bd40b 100644
--- a/src/eventStoreCatchUpSubscription.js
+++ b/src/eventStoreCatchUpSubscription.js
@@ -1,5 +1,4 @@
 var util = require('util');
-var when = require('when');
 
 var SubscriptionDropReason = require('./subscriptionDropReason');
 var results = require('./results');
@@ -130,7 +129,7 @@ EventStoreCatchUpSubscription.prototype._runSubscription = function() {
   var self = this;
   this._stopped = false;
   if (this._verbose) this._log.debug("Catch-up Subscription to %s: pulling events...", logStreamName);
-  when(this._readEventsTill(this._connection, this._resolveLinkTos, this._userCredentials, null, null))
+  this._readEventsTill(this._connection, this._resolveLinkTos, this._userCredentials, null, null)
       .then(function() {
         if (self._shouldStop) return;
         if (self._verbose) self._log.debug("Catch-up Subscription to %s: subscribing...", logStreamName);
diff --git a/src/eventStoreNodeConnection.js b/src/eventStoreNodeConnection.js
index 1ac82af..df9013a 100644
--- a/src/eventStoreNodeConnection.js
+++ b/src/eventStoreNodeConnection.js
@@ -1,6 +1,5 @@
 var util = require('util');
 var uuid = require('uuid');
-var when = require('when');
 var EventEmitter = require('events').EventEmitter;
 var ensure = require('./common/utils/ensure');
 
@@ -70,7 +69,7 @@ Object.defineProperty(EventStoreNodeConnection.prototype, 'connectionName', {
  */
 EventStoreNodeConnection.prototype.connect = function() {
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err) {
       if (err) return reject(err);
       resolve();
@@ -98,7 +97,7 @@ EventStoreNodeConnection.prototype.deleteStream = function(stream, expectedVersi
   if (typeof expectedVersion !== 'number' || expectedVersion % 1 !== 0) throw new TypeError("expectedVersion must be an integer.");
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -125,7 +124,7 @@ EventStoreNodeConnection.prototype.appendToStream = function(stream, expectedVer
   if (!Array.isArray(events)) throw new TypeError("events must be an array.");
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -146,7 +145,7 @@ EventStoreNodeConnection.prototype.appendToStream = function(stream, expectedVer
 EventStoreNodeConnection.prototype.startTransaction = function(stream, expectedVersion, userCredentials) {
   //TODO validations
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -170,7 +169,7 @@ EventStoreNodeConnection.prototype.continueTransaction = function(transactionId,
 
 EventStoreNodeConnection.prototype.transactionalWrite = function(transaction, events, userCredentials) {
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err) {
       if (err) return reject(err);
       resolve();
@@ -183,7 +182,7 @@ EventStoreNodeConnection.prototype.transactionalWrite = function(transaction, ev
 
 EventStoreNodeConnection.prototype.commitTransaction = function(transaction, userCredentials) {
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -210,7 +209,7 @@ EventStoreNodeConnection.prototype.readEvent = function(stream, eventNumber, res
   if (resolveLinkTos && typeof resolveLinkTos !== 'boolean') throw new TypeError("resolveLinkTos must be a boolean.");
 
   var self = this;
-  return when.promise(function(resolve, reject){
+  return new Promise(function(resolve, reject){
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -239,7 +238,7 @@ EventStoreNodeConnection.prototype.readStreamEventsForward = function(
   if (resolveLinkTos && typeof resolveLinkTos !== 'boolean') throw new TypeError("resolveLinkTos must be a boolean.");
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -268,7 +267,7 @@ EventStoreNodeConnection.prototype.readStreamEventsBackward = function(
   if (resolveLinkTos && typeof resolveLinkTos !== 'boolean') throw new TypeError("resolveLinkTos must be a boolean.");
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -293,7 +292,7 @@ EventStoreNodeConnection.prototype.readAllEventsForward = function(
   //TODO validations
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -318,7 +317,7 @@ EventStoreNodeConnection.prototype.readAllEventsBackward = function(
   //TODO validations
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -346,7 +345,7 @@ EventStoreNodeConnection.prototype.subscribeToStream = function(
   if (typeof eventAppeared !== 'function') throw new TypeError("eventAppeared must be a function.");
 
   var self = this;
-  return when.promise(function(resolve,reject) {
+  return new Promise(function(resolve,reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -399,7 +398,7 @@ EventStoreNodeConnection.prototype.subscribeToAll = function(
   if (typeof eventAppeared !== 'function') throw new TypeError("eventAppeared must be a function.");
 
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
@@ -476,7 +475,7 @@ EventStoreNodeConnection.prototype.setStreamMetadataRaw = function(
   if (systemStreams.isMetastream(stream))
     throw new Error(util.format("Setting metadata for metastream '%s' is not supported.", stream));
   var self = this;
-  return when.promise(function(resolve, reject) {
+  return new Promise(function(resolve, reject) {
     function cb(err, result) {
       if (err) return reject(err);
       resolve(result);
diff --git a/src/eventStoreStreamCatchUpSubscription.js b/src/eventStoreStreamCatchUpSubscription.js
index ec632b9..2a6a916 100644
--- a/src/eventStoreStreamCatchUpSubscription.js
+++ b/src/eventStoreStreamCatchUpSubscription.js
@@ -1,5 +1,4 @@
 var util = require('util');
-var when = require('when');
 
 var EventStoreCatchUpSubscription = require('./eventStoreCatchUpSubscription');
 var SliceReadStatus = require('./sliceReadStatus');
@@ -27,9 +26,9 @@ EventStoreStreamCatchUpSubscription.prototype._readEventsTill = function(
 
   function processEvents(events, index) {
     index = index || 0;
-    if (index >= events.length) return when();
+    if (index >= events.length) return Promise.resolve();
 
-    return when.promise(function(resolve, reject) {
+    return new Promise(function(resolve, reject) {
           self._tryProcess(events[index]);
           resolve();
         })
@@ -46,7 +45,7 @@ EventStoreStreamCatchUpSubscription.prototype._readEventsTill = function(
               return processEvents(slice.events)
                   .then(function() {
                     self._nextReadEventNumber = slice.nextEventNumber;
-                    var done = when(lastEventNumber === null ? slice.isEndOfStream : slice.nextEventNumber > lastEventNumber);
+                    var done = Promise.resolve(lastEventNumber === null ? slice.isEndOfStream : slice.nextEventNumber > lastEventNumber);
                     if (!done && slice.isEndOfStream)
                         return done.delay(10);
                     return done;
diff --git a/test/client_test.js b/test/client_test.js
index 4d6fa35..a8b8a87 100644
--- a/test/client_test.js
+++ b/test/client_test.js
@@ -1,5 +1,4 @@
 var util = require('util');
-var when = require('when');
 var uuid = require('uuid');
 var client = require('../src/client');
 var NoopLogger = require('../src/common/log/noopLogger');
@@ -72,11 +71,11 @@ module.exports = {
     this.conn.startTransaction(testStreamName, client.expectedVersion.any)
         .then(function(trx) {
           test.ok(trx, "No transaction.");
-          return when.join(trx, trx.write([createRandomEvent()]));
+          return Promise.all([trx, trx.write([createRandomEvent()])]);
         })
         .then(function(args) {
           var trx = args[0];
-          return when.join(trx, trx.write([createRandomEvent()]));
+          return Promise.all([trx, trx.write([createRandomEvent()])]);
         })
         .then(function(args) {
           var trx = args[0];