diff --git a/PushSharp.Apple/ApnsConnection.cs b/PushSharp.Apple/ApnsConnection.cs
index 0908b166..371151b3 100644
--- a/PushSharp.Apple/ApnsConnection.cs
+++ b/PushSharp.Apple/ApnsConnection.cs
@@ -354,7 +354,8 @@ async Task connect ()
                     (sender, targetHost, localCerts, remoteCert, acceptableIssuers) => certificate);
 
                 try {
-                    stream.AuthenticateAsClient (Configuration.Host, certificates, System.Security.Authentication.SslProtocols.Tls, false);
+                    var tls = System.Security.Authentication.SslProtocols.Tls | System.Security.Authentication.SslProtocols.Tls11 | System.Security.Authentication.SslProtocols.Tls12;
+                    stream.AuthenticateAsClient(Configuration.Host, certificates, tls, false);
                 } catch (System.Security.Authentication.AuthenticationException ex) {
                     throw new ApnsConnectionException ("SSL Stream Failed to Authenticate as Client", ex);
                 }
diff --git a/PushSharp.Apple/ApnsFeedbackService.cs b/PushSharp.Apple/ApnsFeedbackService.cs
index 57fb887a..1d078318 100644
--- a/PushSharp.Apple/ApnsFeedbackService.cs
+++ b/PushSharp.Apple/ApnsFeedbackService.cs
@@ -38,7 +38,8 @@ public void Check ()
                 (sender, cert, chain, sslErrs) => { return true; },
                 (sender, targetHost, localCerts, remoteCert, acceptableIssuers) => { return certificate; });
 
-            stream.AuthenticateAsClient(Configuration.FeedbackHost, certificates, System.Security.Authentication.SslProtocols.Tls, false);
+            var tls = System.Security.Authentication.SslProtocols.Tls | System.Security.Authentication.SslProtocols.Tls11 | System.Security.Authentication.SslProtocols.Tls12;
+            stream.AuthenticateAsClient(Configuration.FeedbackHost, certificates, tls, false);
 
 
             //Set up
diff --git a/README.md b/README.md
index b3ae1f9b..1830f436 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 PushSharp v4.0
 ==============
 
-PushSharp is a server-side library for sending Push Notifications to iOS/OSX (APNS), Android/Chrome (GCM), Windows/Windows Phone, Amazon (ADM) and Blackberry devices!
+PushSharp is a server-side library for sending Push Notifications to iOS/OSX (APNS), Android/Chrome (GCM/FCM), Windows/Windows Phone, Amazon (ADM) and Blackberry devices!
 
 PushSharp v3.0+ is a complete rewrite of the original library, aimed at taking advantage of things like async/await, HttpClient, and generally a better infrastructure using lessons learned from the old code.
 
@@ -39,8 +39,7 @@ apnsBroker.OnNotificationFailed += (notification, aggregateEx) => {
 	aggregateEx.Handle (ex => {
 	
 		// See what kind of exception it was to further diagnose
-		if (ex is ApnsNotificationException) {
-			var notificationException = (ApnsNotificationException)ex;
+		if (ex is ApnsNotificationException notificationException) {
 			
 			// Deal with the failed notification
 			var apnsNotification = notificationException.Notification;
@@ -103,13 +102,19 @@ fbs.Check ();
 ```
 
 
-### GCM Sample Usage
+### GCM/FCM Sample Usage
 
-Here is how you would send a GCM Notification:
+Here is how you would send a GCM/FCM Notification:
 
 ```csharp
-// Configuration
+// Configuration GCM (use this section for GCM)
 var config = new GcmConfiguration ("GCM-SENDER-ID", "AUTH-TOKEN", null);
+var provider = "GCM";
+
+// Configuration FCM (use this section for FCM)
+// var config = new GcmConfiguration("APIKEY");
+// config.GcmUrl = "https://fcm.googleapis.com/fcm/send";
+// var provider = "FCM";
 
 // Create a new broker
 var gcmBroker = new GcmServiceBroker (config);
@@ -120,46 +125,43 @@ gcmBroker.OnNotificationFailed += (notification, aggregateEx) => {
 	aggregateEx.Handle (ex => {
 	
 		// See what kind of exception it was to further diagnose
-		if (ex is GcmNotificationException) {
-			var notificationException = (GcmNotificationException)ex;
+		if (ex is GcmNotificationException notificationException) {
 			
 			// Deal with the failed notification
 			var gcmNotification = notificationException.Notification;
 			var description = notificationException.Description;
 
-			Console.WriteLine ($"GCM Notification Failed: ID={gcmNotification.MessageId}, Desc={description}");
-		} else if (ex is GcmMulticastResultException) {
-			var multicastException = (GcmMulticastResultException)ex;
+			Console.WriteLine ($"{provider} Notification Failed: ID={gcmNotification.MessageId}, Desc={description}");
+		} else if (ex is GcmMulticastResultException multicastException) {
 
 			foreach (var succeededNotification in multicastException.Succeeded) {
-				Console.WriteLine ($"GCM Notification Succeeded: ID={succeededNotification.MessageId}");
+				Console.WriteLine ($"{provider} Notification Succeeded: ID={succeededNotification.MessageId}");
 			}
 
 			foreach (var failedKvp in multicastException.Failed) {
 				var n = failedKvp.Key;
 				var e = failedKvp.Value;
 
-				Console.WriteLine ($"GCM Notification Failed: ID={n.MessageId}, Desc={e.Description}");
+				Console.WriteLine ($"{provider} Notification Failed: ID={n.MessageId}, Desc={e.Description}");
 			}
 
-		} else if (ex is DeviceSubscriptionExpiredException) {
-			var expiredException = (DeviceSubscriptionExpiredException)ex;
+		} else if (ex is DeviceSubscriptionExpiredException expiredException) {
 			
 			var oldId = expiredException.OldSubscriptionId;
 			var newId = expiredException.NewSubscriptionId;
 
 			Console.WriteLine ($"Device RegistrationId Expired: {oldId}");
 
-			if (!string.IsNullOrWhitespace (newId)) {
+			if (!string.IsNullOrWhiteSpace (newId)) {
 				// If this value isn't null, our subscription changed and we should update our database
 				Console.WriteLine ($"Device RegistrationId Changed To: {newId}");
 			}
-		} else if (ex is RetryAfterException) {
-			var retryException = (RetryAfterException)ex;
+		} else if (ex is RetryAfterException retryException) {
+			
 			// If you get rate limited, you should stop sending messages until after the RetryAfterUtc date
-			Console.WriteLine ($"GCM Rate Limited, don't send more until after {retryException.RetryAfterUtc}");
+			Console.WriteLine ($"{provider} Rate Limited, don't send more until after {retryException.RetryAfterUtc}");
 		} else {
-			Console.WriteLine ("GCM Notification Failed for some unknown reason");
+			Console.WriteLine ("{provider} Notification Failed for some unknown reason");
 		}
 
 		// Mark it as handled
@@ -168,7 +170,7 @@ gcmBroker.OnNotificationFailed += (notification, aggregateEx) => {
 };
 
 gcmBroker.OnNotificationSucceeded += (notification) => {
-	Console.WriteLine ("GCM Notification Sent!");
+	Console.WriteLine ("{provider} Notification Sent!");
 };
 
 // Start the broker
@@ -190,7 +192,7 @@ foreach (var regId in MY_REGISTRATION_IDS) {
 gcmBroker.Stop ();
 ```
 
-#### Components of a GCM Notification
+#### Components of a GCM/FCM Notification
 
 GCM notifications are much more customizable than Apple Push Notifications. More information about the messaging concepts and options can be found [here](https://developers.google.com/cloud-messaging/concept-options#components-of-a-message).
 
@@ -212,8 +214,7 @@ wnsBroker.OnNotificationFailed += (notification, aggregateEx) => {
 	aggregateEx.Handle (ex => {
 	
 		// See what kind of exception it was to further diagnose
-		if (ex is WnsNotificationException) {
-			var notificationException = (WnsNotificationException)ex;
+		if (ex is WnsNotificationException notificationException) {
 			Console.WriteLine ($"WNS Notification Failed: {notificationException.Message}");
 		} else {
 			Console.WriteLine ("WNS Notification Failed for some (Unknown Reason)");