diff --git a/csi.proto b/csi.proto
index ee73aa7a..dc60c628 100644
--- a/csi.proto
+++ b/csi.proto
@@ -7,6 +7,7 @@ import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";
 
 option go_package = "csi";
+option csharp_namespace = "csi";
 
 extend google.protobuf.EnumOptions {
   // Indicates that this enum is OPTIONAL and part of an experimental
diff --git a/spec.md b/spec.md
index bd537fee..11b05737 100644
--- a/spec.md
+++ b/spec.md
@@ -279,6 +279,7 @@ import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";
 
 option go_package = "csi";
+option csharp_namespace = "csi";
 
 extend google.protobuf.EnumOptions {
   // Indicates that this enum is OPTIONAL and part of an experimental