diff --git a/Source/MQTTnet/Serializer/MqttPacketWriter.cs b/Source/MQTTnet/Serializer/MqttPacketWriter.cs
index f6784d4..c7f1bc2 100644
--- a/Source/MQTTnet/Serializer/MqttPacketWriter.cs
+++ b/Source/MQTTnet/Serializer/MqttPacketWriter.cs
@@ -99,7 +99,7 @@ namespace MQTTnet.Serializer
 
         public void Reset()
         {
-            Length = 0;
+            Length = 5;
         }
 
         public void Seek(int offset)