diff --git a/lib/docker.js b/lib/docker.js
index a59ec37..7240c40 100644
--- a/lib/docker.js
+++ b/lib/docker.js
@@ -20,8 +20,10 @@ var EventEmitter = require('events').EventEmitter,
 
 var Docker = function(opts) {
   if (!(this instanceof Docker)) return new Docker(opts);
+
   this.modem = new Modem(opts);
-  this.modem.Promise = opts.Promise || global.Promise;
+
+  this.modem.Promise = opts && opts.Promise || global.Promise;
 };
 
 /**
diff --git a/package.json b/package.json
index e37ad1f..157cab7 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "dockerode",
   "description": "Docker Remote API module.",
-  "version": "2.3.3",
+  "version": "2.3.4",
   "author": "Pedro Dias <petermdias@gmail.com>",
   "maintainers": [
     "apocas <petermdias@gmail.com>"