diff --git a/Source/MQTTnet/Adapter/MqttChannelAdapter.cs b/Source/MQTTnet/Adapter/MqttChannelAdapter.cs
index f364168..d7585cb 100644
--- a/Source/MQTTnet/Adapter/MqttChannelAdapter.cs
+++ b/Source/MQTTnet/Adapter/MqttChannelAdapter.cs
@@ -272,7 +272,9 @@ namespace MQTTnet.Adapter
             if (disposing)
             {
                 _channel?.Dispose();
+                _writerSemaphore?.Dispose();
             }
+            
             base.Dispose(disposing);
         }