diff --git a/Socket.IO-Client-Swift.podspec b/Socket.IO-Client-Swift.podspec
index 36c8c06..781ee3e 100644
--- a/Socket.IO-Client-Swift.podspec
+++ b/Socket.IO-Client-Swift.podspec
@@ -17,5 +17,6 @@ Pod::Spec.new do |s|
   s.source       = { :git => "https://github.com/socketio/socket.io-client-swift.git", :tag => 'v8.1.0' }
   s.source_files  = "Source/**/*.swift"
   s.requires_arc = true
+  s.pod_target_xcconfig = {'SWIFT_VERSION' => '3.0'}
   # s.dependency 'Starscream', '~> 0.9' # currently this repo includes Starscream swift files
 end
diff --git a/Source/SocketAckEmitter.swift b/Source/SocketAckEmitter.swift
index 6b86460..4af43e7 100644
--- a/Source/SocketAckEmitter.swift
+++ b/Source/SocketAckEmitter.swift
@@ -27,6 +27,10 @@ import Foundation
 public final class SocketAckEmitter : NSObject {
     let socket: SocketIOClient
     let ackNum: Int
+
+    public var expected: Bool {
+        return ackNum != -1
+    }
     
     init(socket: SocketIOClient, ackNum: Int) {
         self.socket = socket
@@ -44,6 +48,7 @@ public final class SocketAckEmitter : NSObject {
         
         socket.emitAck(ackNum, with: items)
     }
+        
 }
 
 public final class OnAckCallback : NSObject {