diff --git a/package.json b/package.json
index 18d618b..99b7ccc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@hibas123/jrpcgen",
-   "version": "1.0.21",
+   "version": "1.0.22",
    "main": "lib/index.js",
    "license": "MIT",
    "packageManager": "yarn@3.1.1",
diff --git a/templates/CSharp/JRpcTransport.cs b/templates/CSharp/JRpcTransport.cs
index 90e6e07..5f0d2c3 100644
--- a/templates/CSharp/JRpcTransport.cs
+++ b/templates/CSharp/JRpcTransport.cs
@@ -5,11 +5,11 @@ namespace __NAMESPACE__;
 public delegate void NotifyPacket(string data);
 
 public abstract class JRpcTransport {
-   public event NotifyPacket OnPacket;
+   public event NotifyPacket? OnPacket;
    public abstract Task Write(string data);
 
    // TODO: Spend some time finding a better permission, but it is fine for now
    public void SendPacketEvent(string data) {
-      this.OnPacket.Invoke(data);
+      this.OnPacket?.Invoke(data);
    }
 }