diff --git a/Source/Extensions/NSURL+TrailingSlash.swift b/Source/Extensions/NSURL+TrailingSlash.swift
index 641407a..662b071 100644
--- a/Source/Extensions/NSURL+TrailingSlash.swift
+++ b/Source/Extensions/NSURL+TrailingSlash.swift
@@ -38,7 +38,12 @@ internal extension NSURL {
     }
     
     var relativeURL: NSURL? {
-        return NSURL(string: "\(self.scheme!)://\(self.host!):\(self.port!)")
+        if let port = self.port {
+            return NSURL(string: "\(self.scheme!)://\(self.host!):\(port)")
+        }
+        else {
+            return NSURL(string: "\(self.scheme!)://\(self.host!)")
+        }
     }
     
 }
diff --git a/Source/SocketIOWebSocket.swift b/Source/SocketIOWebSocket.swift
index 8da42e6..c39f2bb 100644
--- a/Source/SocketIOWebSocket.swift
+++ b/Source/SocketIOWebSocket.swift
@@ -11,6 +11,7 @@ import Foundation
 class SocketIOWebSocket: SocketIOTransport, WebSocketDelegate {
     
     private var socket: WebSocket!
+    private let defaultPort = 80
     
     private var nsp: String {
         return delegate.options.namespace
@@ -26,7 +27,16 @@ class SocketIOWebSocket: SocketIOTransport, WebSocketDelegate {
             return
         }
         
-        if let scheme = hostUrl.scheme, let host = hostUrl.host, let port = hostUrl.port {
+        // Check current port
+        let port: Int
+        if let hostPort = hostUrl.port {
+            port = hostPort.integerValue
+        }
+        else {
+            port = defaultPort
+        }
+        
+        if let scheme = hostUrl.scheme, let host = hostUrl.host {
             // Establish connection
             if scheme.lowercaseString == "http" {
                 // Standard