diff --git a/.github/workflows/ReleaseNotes.md b/.github/workflows/ReleaseNotes.md
index 4cf58e59..bd6f0335 100644
--- a/.github/workflows/ReleaseNotes.md
+++ b/.github/workflows/ReleaseNotes.md
@@ -1,2 +1,3 @@
+* [Core] MQTT Packets being sent over web socket transport are now setting the web socket frame boundaries correctly (#1499).
 * [Client] Keep alive mechanism now uses the configured timeout value from the options (thanks to @Stannieman, #1495).
-* [Core] MQTT Packets being sent over web socket transport are now setting the web socket frame boundaries correctly (#1499).
\ No newline at end of file
+* [Server] A DISCONNECT packet is no longer sent to MQTT clients < 5.0.0 (thanks to @logicaloud, #1506).
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cb2c15da..8ae88065 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,7 @@ name: CI
 on: [push, pull_request]
 
 env:
-  VERSION: "4.1.0.${{github.run_number}}"
+  VERSION: "4.1.1.${{github.run_number}}"
 
 jobs:
   build:
diff --git a/Source/MQTTnet/Server/Internal/MqttClient.cs b/Source/MQTTnet/Server/Internal/MqttClient.cs
index c79447e9..2982961c 100644
--- a/Source/MQTTnet/Server/Internal/MqttClient.cs
+++ b/Source/MQTTnet/Server/Internal/MqttClient.cs
@@ -147,15 +147,20 @@ namespace MQTTnet.Server
         {
             IsRunning = false;
 
-            // Potentially send disconnect reason to MQTT 5 clients
-
-            if (ChannelAdapter.PacketFormatterAdapter.ProtocolVersion == MqttProtocolVersion.V500 && reason != MqttDisconnectReasonCode.NormalDisconnection)            
+            // Sending DISCONNECT packets from the server to the client is only supported when using MQTTv5+.
+            if (ChannelAdapter.PacketFormatterAdapter.ProtocolVersion == MqttProtocolVersion.V500)
             {
-                // Is is very important to send the DISCONNECT packet here BEFORE cancelling the
-                // token because the entire connection is closed (disposed) as soon as the cancellation
-                // token is cancelled. To there is no chance that the DISCONNECT packet will ever arrive
-                // at the client!
-                await TrySendDisconnectPacket(reason).ConfigureAwait(false);
+                // The Client or Server MAY send a DISCONNECT packet before closing the Network Connection.
+                // This library does not sent a DISCONNECT packet for a normal disconnection. Maybe adding
+                // a configuration option is requested in the future.
+                if (reason != MqttDisconnectReasonCode.NormalDisconnection)
+                {
+                    // Is is very important to send the DISCONNECT packet here BEFORE cancelling the
+                    // token because the entire connection is closed (disposed) as soon as the cancellation
+                    // token is cancelled. To there is no chance that the DISCONNECT packet will ever arrive
+                    // at the client!
+                    await TrySendDisconnectPacket(reason).ConfigureAwait(false);
+                }
             }
 
             StopInternal();