diff --git a/Cartfile.resolved b/Cartfile.resolved
index c3deb60..5825522 100644
--- a/Cartfile.resolved
+++ b/Cartfile.resolved
@@ -1,2 +1,2 @@
-github "pvzig/Starscream" "98d7ccea30621d51a93ee5c155b3f670e37e037b"
-github "pvzig/swifter" "8adfae89a6d34cfea1c20d53d8112d1d69e01bd0"
+github "pvzig/Starscream" "2fde5c5eb9302439e634753c3aacc794ca2e42e8"
+github "pvzig/swifter" "ddbebdde19360a2c9e4e01e5a0642dd12082cc92"
diff --git a/SlackKit/Sources/Client+EventHandling.swift b/SlackKit/Sources/Client+EventHandling.swift
index ad38aee..4688bdd 100644
--- a/SlackKit/Sources/Client+EventHandling.swift
+++ b/SlackKit/Sources/Client+EventHandling.swift
@@ -80,11 +80,11 @@ internal extension Client {
         channelEventsDelegate?.userTyping(self, channel: channel, user: user)
 
         let timeout = DispatchTime.now() + Double(Int64(5.0 * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)
-        DispatchQueue.main.after(when: timeout) {
+        DispatchQueue.main.asyncAfter(deadline: timeout, execute: {
             if let index = self.channels[channelID]?.usersTyping.index(of: userID) {
                 self.channels[channelID]?.usersTyping.remove(at: index)
             }
-        }
+        })
     }
 
     func channelMarked(_ event: Event) {
diff --git a/SlackKit/Sources/Client+Utilities.swift b/SlackKit/Sources/Client+Utilities.swift
index 26b9f13..0c8d118 100644
--- a/SlackKit/Sources/Client+Utilities.swift
+++ b/SlackKit/Sources/Client+Utilities.swift
@@ -21,7 +21,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-public enum ClientError: ErrorProtocol {
+public enum ClientError: Error {
     case channelDoesNotExist
     case userDoesNotExist
 }
diff --git a/SlackKit/Sources/Client.swift b/SlackKit/Sources/Client.swift
index b80eed8..457bb54 100644
--- a/SlackKit/Sources/Client.swift
+++ b/SlackKit/Sources/Client.swift
@@ -44,7 +44,7 @@ public final class Client: WebSocketDelegate {
     }
 
     internal var webSocket: WebSocket?
-    private let pingPongQueue = DispatchQueue(label: "com.launchsoft.SlackKit", attributes: DispatchQueueAttributes.serial)
+    private let pingPongQueue = DispatchQueue(label: "com.launchsoft.SlackKit")
     internal var ping: Double?
     internal var pong: Double?
     internal var options: ClientOptions?
@@ -128,7 +128,7 @@ public final class Client: WebSocketDelegate {
     //MARK: - RTM Ping
     private func pingRTMServerAtInterval(_ interval: TimeInterval) {
         let delay = DispatchTime.now() + Double(Int64(interval * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)
-        pingPongQueue.after(when: delay, execute: {
+        pingPongQueue.asyncAfter(deadline: delay, execute: {
             guard self.connected && self.timeoutCheck() else {
                 self.disconnect()
                 return
diff --git a/SlackKit/Sources/Extensions.swift b/SlackKit/Sources/Extensions.swift
index 55f68c4..a0d2049 100644
--- a/SlackKit/Sources/Extensions.swift
+++ b/SlackKit/Sources/Extensions.swift
@@ -42,7 +42,7 @@ internal extension String {
 
 }
 
-internal extension Dictionary where Key: StringLiteralConvertible, Value: AnyObject {
+internal extension Dictionary where Key: ExpressibleByStringLiteral, Value: AnyObject {
 
     var requestStringFromParameters: String {
         var requestString = ""
diff --git a/SlackKit/Sources/SlackError.swift b/SlackKit/Sources/SlackError.swift
index 18faa3a..283ea9b 100644
--- a/SlackKit/Sources/SlackError.swift
+++ b/SlackKit/Sources/SlackError.swift
@@ -21,7 +21,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-public enum SlackError: String, ErrorProtocol {
+public enum SlackError: String, Error {
     case AccountInactive = "account_inactive"
     case AlreadyArchived = "already_archived"
     case AlreadyInChannel = "already_in_channel"