diff --git a/SwiftIO/SocketEngineClient.swift b/SwiftIO/SocketEngineClient.swift
index 22e2aab..8e984c7 100644
--- a/SwiftIO/SocketEngineClient.swift
+++ b/SwiftIO/SocketEngineClient.swift
@@ -35,7 +35,7 @@ import Foundation
     
     func parseSocketMessage(msg:String)
     func parseBinaryData(data:NSData)
-    func pollingDidFail(err:NSError?)
+    func pollingDidFail(err:NSError)
     func webSocketDidCloseWithCode(code:Int, reason:String, wasClean:Bool)
     func webSocketDidFailWithError(error:NSError)
-}
\ No newline at end of file
+}