diff --git a/_includes/features_list.php b/_includes/features_list.php
index f01bc19..bef8288 100644
--- a/_includes/features_list.php
+++ b/_includes/features_list.php
@@ -10,6 +10,10 @@
         "name" => "MQTT 3.1.1",
         "tooltip" => "MQTT version 3.1.1 specification."
     ),
+    "mqtt-50" => array(
+        "name" => "MQTT 5.0",
+        "tooltip" => "MQTT version 5.0 specification."
+    ),
     "lwt" => array(
         "name" => "LWT",
         "tooltip" => "Last Will and Testament messages."
diff --git a/clients/c/index.php b/clients/c/index.php
index c95af75..2ccefb8 100644
--- a/clients/c/index.php
+++ b/clients/c/index.php
@@ -17,12 +17,13 @@
     $features = array(
         "mqtt-31" => true,
         "mqtt-311" => true,
+        "mqtt-50" => true,
         "lwt" => true,
         "tls" => true,
         "persistence" => true,
         "reconnect" => true,
         "buffering" => true,
-        "websocket" => false,
+        "websocket" => true,
         "tcp" => true,
         "async" => true,
         "sync" => true,