diff --git a/dotnet/src/Microsoft.AutoGen/Agents/AgentBase.cs b/dotnet/src/Microsoft.AutoGen/Agents/AgentBase.cs
index 1d48147c11ed..f929745274f1 100644
--- a/dotnet/src/Microsoft.AutoGen/Agents/AgentBase.cs
+++ b/dotnet/src/Microsoft.AutoGen/Agents/AgentBase.cs
@@ -44,7 +44,7 @@ protected AgentBase(
                 TypeSubscription = new TypeSubscription
                 {
                     AgentType = this.AgentId.Type,
-                    TopicType = this.AgentId.Key
+                    TopicType = this.AgentId.Type + "/" + this.AgentId.Key
                 }
             }
         };