diff --git a/browser/BrowserPerf.proto b/browser/BrowserPerf.proto
index 1a3ca82815e333309030634120c01f1b850462f1..793492de97543670fb5ff80f774f8e6d098683bd 100644
--- a/browser/BrowserPerf.proto
+++ b/browser/BrowserPerf.proto
@@ -20,6 +20,7 @@ syntax = "proto3";
 
 option java_multiple_files = true;
 option java_package = "org.apache.skywalking.apm.network.language.agent.v3";
+option csharp_namespace = "SkyWalking.NetworkProtocol.V3";
 option go_package = "skywalking/network/language/agent/v3";
 
 import "common/Common.proto";
diff --git a/service-mesh-probe/service-mesh.proto b/service-mesh-probe/service-mesh.proto
index 5ce7dc52c4eef1c4f23e85c543bb34c41010b8e2..4cdc18ff5fc85364aedea34743c598479d8a97ec 100644
--- a/service-mesh-probe/service-mesh.proto
+++ b/service-mesh-probe/service-mesh.proto
@@ -20,6 +20,7 @@ syntax = "proto3";
 
 option java_multiple_files = true;
 option java_package = "org.apache.skywalking.apm.network.servicemesh.v3";
+option csharp_namespace = "SkyWalking.NetworkProtocol.V3";
 option go_package = "skywalking/network/servicemesh/v3";
 
 import "common/Common.proto";