diff --git a/README.md b/README.md
index 69ed99c..23642f2 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ Carthage
 -----------------
 Add this line to your `Cartfile`:
 ```
-github "socketio/socket.io-client-swift" ~> 4.0.3 # Or latest version
+github "socketio/socket.io-client-swift" ~> 4.0.4 # Or latest version
 ```
 
 Run `carthage update --platform ios,macosx`.
@@ -83,7 +83,7 @@ source 'https://github.com/CocoaPods/Specs.git'
 platform :ios, '8.0'
 use_frameworks!
 
-pod 'Socket.IO-Client-Swift', '~> 4.0.3' # Or latest version
+pod 'Socket.IO-Client-Swift', '~> 4.0.4' # Or latest version
 ```
 
 Install pods:
@@ -111,7 +111,7 @@ CocoaSeeds
 Add this line to your `Seedfile`:
 
 ```
-github "socketio/socket.io-client-swift", "v4.0.3", :files => "SocketIOClientSwift/*.swift" # Or latest version
+github "socketio/socket.io-client-swift", "v4.0.4", :files => "SocketIOClientSwift/*.swift" # Or latest version
 ```
 
 Run `seed install`.
@@ -143,6 +143,7 @@ case SessionDelegate(NSURLSessionDelegate) // Sets an NSURLSessionDelegate for t
 case Path(String) // If the server uses a custom path. ex: `"/swift"`. Default is `""`
 case ExtraHeaders([String: String]) // Adds custom headers to the initial request. Default is nil.
 case HandleQueue(dispatch_queue_t) // The dispatch queue that handlers are run on. Default is the main queue.
+case VoipEnabled(Bool) // Only use this option if you're using the client with VoIP services. Changes the way the WebSocket is created. Default is false
 ```
 Methods
 -------
diff --git a/Socket.IO-Client-Swift.podspec b/Socket.IO-Client-Swift.podspec
index 60813b6..4176a4e 100644
--- a/Socket.IO-Client-Swift.podspec
+++ b/Socket.IO-Client-Swift.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "Socket.IO-Client-Swift"
-  s.version      = "4.0.3"
+  s.version      = "4.0.4"
   s.summary      = "Socket.IO-client for iOS and OS X"
   s.description  = <<-DESC
                    Socket.IO-client for iOS and OS X.
@@ -12,7 +12,7 @@ Pod::Spec.new do |s|
   s.author       = { "Erik" => "nuclear.ace@gmail.com" }
   s.ios.deployment_target = '8.0'
   s.osx.deployment_target = '10.10'
-  s.source       = { :git => "https://github.com/socketio/socket.io-client-swift.git", :tag => 'v4.0.3' }
+  s.source       = { :git => "https://github.com/socketio/socket.io-client-swift.git", :tag => 'v4.0.4' }
   s.source_files  = "SocketIOClientSwift/**/*.swift"
   s.requires_arc = true
   # s.dependency 'Starscream', '~> 0.9' # currently this repo includes Starscream swift files
diff --git a/SocketIOClientSwift/SocketEngine.swift b/SocketIOClientSwift/SocketEngine.swift
index 8cd2980..fe74f27 100644
--- a/SocketIOClientSwift/SocketEngine.swift
+++ b/SocketIOClientSwift/SocketEngine.swift
@@ -63,6 +63,7 @@ public final class SocketEngine: NSObject, SocketEngineSpec, WebSocketDelegate {
     private var probing = false
     private var probeWait = ProbeWaitQueue()
     private var session: NSURLSession!
+    private var voipEnabled = false
     private var waitingForPoll = false
     private var waitingForPost = false
     private var websocketConnected = false
@@ -71,8 +72,9 @@ public final class SocketEngine: NSObject, SocketEngineSpec, WebSocketDelegate {
     private(set) var polling = true
     private(set) var websocket = false
     
-    init(client: SocketEngineClient, options: Set<SocketIOClientOption>) {
+    public init(client: SocketEngineClient, options: Set<SocketIOClientOption>) {
         self.client = client
+
         for option in options {
             switch option {
             case .SessionDelegate(let delegate):
@@ -89,6 +91,8 @@ public final class SocketEngine: NSObject, SocketEngineSpec, WebSocketDelegate {
                 socketPath = path
             case .ExtraHeaders(let headers):
                 extraHeaders = headers
+            case .VoipEnabled(let enable):
+                voipEnabled = enable
             default:
                 continue
             }
@@ -217,6 +221,7 @@ public final class SocketEngine: NSObject, SocketEngineSpec, WebSocketDelegate {
         }
 
         ws?.queue = handleQueue
+        ws?.voipEnabled = voipEnabled
         ws?.delegate = self
 
         if connect {
diff --git a/SocketIOClientSwift/SocketIOClientOption.swift b/SocketIOClientSwift/SocketIOClientOption.swift
index 11a5b01..7909d96 100644
--- a/SocketIOClientSwift/SocketIOClientOption.swift
+++ b/SocketIOClientSwift/SocketIOClientOption.swift
@@ -39,6 +39,7 @@ public enum SocketIOClientOption: CustomStringConvertible, Hashable {
     case Path(String)
     case ExtraHeaders([String: String])
     case HandleQueue(dispatch_queue_t)
+    case VoipEnabled(Bool)
     
     public var description: String {
         if let label = Mirror(reflecting: self).children.first?.label {
@@ -82,6 +83,8 @@ public enum SocketIOClientOption: CustomStringConvertible, Hashable {
             return .ExtraHeaders(value as! [String: String])
         case "handleQueue" where value is dispatch_queue_t:
             return .HandleQueue(value as! dispatch_queue_t)
+        case "voipEnabled" where value is Bool:
+            return .VoipEnabled(value as! Bool)
         default:
             return nil
         }