diff --git a/Source/SocketAckEmitter.swift b/Source/SocketAckEmitter.swift
index 4af43e7..5546f1d 100644
--- a/Source/SocketAckEmitter.swift
+++ b/Source/SocketAckEmitter.swift
@@ -66,7 +66,7 @@ public final class OnAckCallback : NSObject {
         DefaultSocketLogger.Logger.log("OnAckCallback for \(ackNumber) being released", type: "OnAckCallback")
     }
     
-    public func timingOut(after seconds: Int, callback: @escaping AckCallback) {
+    @objc public func timingOut(after seconds: Int, callback: @escaping AckCallback) {
         guard let socket = self.socket else { return }
         
         socket.ackQueue.sync() {
diff --git a/Source/SocketEngine.swift b/Source/SocketEngine.swift
index 3bf4ae6..4e0d99c 100644
--- a/Source/SocketEngine.swift
+++ b/Source/SocketEngine.swift
@@ -154,7 +154,7 @@ public final class SocketEngine : NSObject, URLSessionDelegate, SocketEnginePoll
 
     private func handleBase64(message: String) {
         // binary in base64 string
-        let noPrefix = message[message.index(message.startIndex, offsetBy: 2)..<message.endIndex]
+        let noPrefix = String(message[message.index(message.startIndex, offsetBy: 2)..<message.endIndex])
         
         if let data = NSData(base64Encoded: noPrefix, options: .ignoreUnknownCharacters) {
             client?.parseEngineBinaryData(data as Data)
@@ -437,13 +437,13 @@ public final class SocketEngine : NSObject, URLSessionDelegate, SocketEnginePoll
 
         switch type {
         case .message:
-            handleMessage(String(fixedString.characters.dropFirst()))
+            handleMessage(String(fixedString.dropFirst()))
         case .noop:
             handleNOOP()
         case .pong:
             handlePong(with: fixedString)
         case .open:
-            handleOpen(openData: String(fixedString.characters.dropFirst()))
+            handleOpen(openData: String(fixedString.dropFirst()))
         case .close:
             handleClose(fixedString)
         default:
diff --git a/Source/SocketEnginePollable.swift b/Source/SocketEnginePollable.swift
index b050975..808c486 100644
--- a/Source/SocketEnginePollable.swift
+++ b/Source/SocketEnginePollable.swift
@@ -68,7 +68,7 @@ extension SocketEnginePollable {
         var postStr = ""
         
         for packet in postWait {
-            let len = packet.characters.count
+            let len = packet.count
             
             postStr += "\(len):\(packet)"
         }
@@ -183,7 +183,7 @@ extension SocketEnginePollable {
     }
     
     func parsePollingMessage(_ str: String) {
-        guard str.characters.count != 1 else { return }
+        guard str.count != 1 else { return }
         
         var reader = SocketStringReader(message: str)
         
diff --git a/Source/SocketIOClient.swift b/Source/SocketIOClient.swift
index fb872c1..3b36c9e 100644
--- a/Source/SocketIOClient.swift
+++ b/Source/SocketIOClient.swift
@@ -108,7 +108,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     
     /// Not so type safe way to create a SocketIOClient, meant for Objective-C compatiblity.
     /// If using Swift it's recommended to use `init(socketURL: NSURL, options: Set<SocketIOClientOption>)`
-    public convenience init(socketURL: NSURL, config: NSDictionary?) {
+    @objc public convenience init(socketURL: NSURL, config: NSDictionary?) {
         self.init(socketURL: socketURL as URL, config: config?.toSocketConfiguration() ?? [])
     }
 
@@ -132,7 +132,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
 
     /// Connect to the server. If we aren't connected after timeoutAfter, call withHandler
     /// 0 Never times out
-    public func connect(timeoutAfter: Int, withHandler handler: (() -> Void)?) {
+    @objc public func connect(timeoutAfter: Int, withHandler handler: (() -> Void)?) {
         assert(timeoutAfter >= 0, "Invalid timeout: \(timeoutAfter)")
 
         guard status != .connected else {
@@ -196,7 +196,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     }
 
     /// Disconnects the socket.
-    public func disconnect() {
+    @objc public func disconnect() {
         DefaultSocketLogger.Logger.log("Closing socket", type: logType)
 
         didDisconnect(reason: "Disconnect")
@@ -208,7 +208,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     }
 
     /// Same as emit, but meant for Objective-C
-    public func emit(_ event: String, with items: [Any]) {
+    @objc public func emit(_ event: String, with items: [Any]) {
         guard status == .connected else {
             handleEvent("error", data: ["Tried emitting \(event) when not connected"], isInternalMessage: true)
             return
@@ -224,7 +224,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     }
 
     /// Same as emitWithAck, but for Objective-C
-    public func emitWithAck(_ event: String, with items: [Any]) -> OnAckCallback {
+    @objc public func emitWithAck(_ event: String, with items: [Any]) -> OnAckCallback {
         return createOnAck([event] + items)
     }
 
@@ -347,7 +347,7 @@ public final class SocketIOClient : NSObject, SocketEngineClient, SocketParsable
     /// Adds a handler for an event.
     /// Returns: A unique id for the handler
     @discardableResult
-    public func on(_ event: String, callback: @escaping NormalCallback) -> UUID {
+    @objc public func on(_ event: String, callback: @escaping NormalCallback) -> UUID {
         DefaultSocketLogger.Logger.log("Adding handler for event: %@", type: logType, args: event)
 
         let handler = SocketEventHandler(event: event, id: UUID(), callback: callback)
diff --git a/Source/SocketParsable.swift b/Source/SocketParsable.swift
index 7c9ce21..1fd69ef 100644
--- a/Source/SocketParsable.swift
+++ b/Source/SocketParsable.swift
@@ -109,7 +109,7 @@ extension SocketParsable {
         
         
         
-        var dataArray = message[message.characters.index(reader.currentIndex, offsetBy: 1)..<message.endIndex]
+        var dataArray = String(message[message.index(reader.currentIndex, offsetBy: 1)..<message.endIndex])
         
         if type == .error && !dataArray.hasPrefix("[") && !dataArray.hasSuffix("]") {
             dataArray = "[" + dataArray + "]"
diff --git a/Source/SocketStringReader.swift b/Source/SocketStringReader.swift
index 8bdb4d4..9a30daa 100644
--- a/Source/SocketStringReader.swift
+++ b/Source/SocketStringReader.swift
@@ -40,17 +40,17 @@ struct SocketStringReader {
     
     @discardableResult
     mutating func advance(by: Int) -> String.Index {
-        currentIndex = message.characters.index(currentIndex, offsetBy: by)
+        currentIndex = message.index(currentIndex, offsetBy: by)
         
         return currentIndex
     }
     
     mutating func read(count: Int) -> String {
-        let readString = message[currentIndex..<message.characters.index(currentIndex, offsetBy: count)]
+        let readString = message[currentIndex..<message.index(currentIndex, offsetBy: count)]
         
         advance(by: count)
         
-        return readString
+        return String(readString)
     }
     
     mutating func readUntilOccurence(of string: String) -> String {
@@ -59,15 +59,15 @@ struct SocketStringReader {
         guard let foundRange = substring.range(of: string) else {
             currentIndex = message.endIndex
             
-            return substring
+            return String(substring)
         }
         
-        advance(by: message.characters.distance(from: message.characters.startIndex, to: foundRange.lowerBound) + 1)
+        advance(by: message.distance(from: message.startIndex, to: foundRange.lowerBound) + 1)
         
-        return substring.substring(to: foundRange.lowerBound)
+        return String(substring[..<foundRange.lowerBound])
     }
     
     mutating func readUntilEnd() -> String {
-        return read(count: message.characters.distance(from: currentIndex, to: message.endIndex))
+        return read(count: message.distance(from: currentIndex, to: message.endIndex))
     }
 }
diff --git a/Source/WebSocket.swift b/Source/WebSocket.swift
index 34152af..f57ec3d 100644
--- a/Source/WebSocket.swift
+++ b/Source/WebSocket.swift
@@ -115,7 +115,7 @@ open class WebSocket : NSObject, StreamDelegate {
     
     
     // MARK: - Block based API.
-    public var onConnect: ((Void) -> Void)?
+    public var onConnect: (() -> Void)?
     public var onDisconnect: ((NSError?) -> Void)?
     public var onText: ((String) -> Void)?
     public var onData: ((Data) -> Void)?