diff --git a/SocketIO-MacTests/SocketSideEffectTest.swift b/SocketIO-MacTests/SocketSideEffectTest.swift
index 7f53b51..7f4bba6 100644
--- a/SocketIO-MacTests/SocketSideEffectTest.swift
+++ b/SocketIO-MacTests/SocketSideEffectTest.swift
@@ -98,7 +98,7 @@ class SocketSideEffectTest: XCTestCase {
         XCTAssertEqual(socket.testHandlers.count, 1)
         socket.on("test") {data, ack in }
         XCTAssertEqual(socket.testHandlers.count, 2)
-        socket.off(event: "test")
+        socket.off("test")
         XCTAssertEqual(socket.testHandlers.count, 0)
     }
     
diff --git a/Source/SocketEngine.swift b/Source/SocketEngine.swift
index d48e75b..610b832 100644
--- a/Source/SocketEngine.swift
+++ b/Source/SocketEngine.swift
@@ -156,7 +156,7 @@ public final class SocketEngine : NSObject, SocketEnginePollable, SocketEngineWe
             // binary in base64 string
             let noPrefix = message[message.characters.index(message.startIndex, offsetBy: 2)..<message.endIndex]
     
-            if let data = Data(base64Encoded: noPrefix, options: NSData.Base64EncodingOptions(rawValue: 0)) {
+            if let data = Data(base64Encoded: noPrefix, options: Data.Base64EncodingOptions(rawValue: 0)) {
                 client?.parseEngineBinaryData(data)
             }
             
diff --git a/Source/SocketEngineSpec.swift b/Source/SocketEngineSpec.swift
index d78cc1c..d39d463 100644
--- a/Source/SocketEngineSpec.swift
+++ b/Source/SocketEngineSpec.swift
@@ -84,7 +84,7 @@ extension SocketEngineSpec {
             
             return .left(mutData as Data)
         } else {
-            let str = "b4" + data.base64EncodedString(NSData.Base64EncodingOptions(rawValue: 0))
+            let str = "b4" + data.base64EncodedString(Data.Base64EncodingOptions(rawValue: 0))
             
             return .right(str)
         }
diff --git a/Source/SocketIOClient.swift b/Source/SocketIOClient.swift
index 56031f3..d56cfb0 100644
--- a/Source/SocketIOClient.swift
+++ b/Source/SocketIOClient.swift
@@ -331,7 +331,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     }
 
     /// Removes handler(s) based on name
-    public func off(event: String) {
+    public func off(_ event: String) {
         DefaultSocketLogger.Logger.log("Removing handler for event: %@", type: logType, args: event)
 
         handlers = handlers.filter({ $0.event != event })
diff --git a/Source/SocketTypes.swift b/Source/SocketTypes.swift
index 2409e26..6e569a8 100644
--- a/Source/SocketTypes.swift
+++ b/Source/SocketTypes.swift
@@ -33,6 +33,7 @@ extension Double : SocketData {}
 extension Int : SocketData {}
 extension NSArray : SocketData {}
 extension Data : SocketData {}
+extension NSData : SocketData {}
 extension NSDictionary : SocketData {}
 extension NSString : SocketData {}
 extension NSNull : SocketData {}
diff --git a/Source/WebSocket/WebSocket.swift b/Source/WebSocket/WebSocket.swift
index 0f8d1c3..e661c45 100644
--- a/Source/WebSocket/WebSocket.swift
+++ b/Source/WebSocket/WebSocket.swift
@@ -270,7 +270,7 @@ public class WebSocket : NSObject, StreamDelegate {
             key += "\(Character(uni))"
         }
         let data = key.data(using: String.Encoding.utf8)
-        let baseKey = data?.base64EncodedString(NSData.Base64EncodingOptions(rawValue: 0))
+        let baseKey = data?.base64EncodedString(Data.Base64EncodingOptions(rawValue: 0))
         return baseKey!
     }
     
@@ -420,9 +420,9 @@ public class WebSocket : NSObject, StreamDelegate {
             let data = inputQueue[0]
             var work = data
             if let fragBuffer = fragBuffer {
-                var combine = NSData(data: fragBuffer) as Data
+                let combine = NSMutableData(data: fragBuffer)
                 combine.append(data)
-                work = combine
+                work = combine as Data
                 self.fragBuffer = nil
             }
             let buffer = UnsafePointer<UInt8>((work as NSData).bytes)