diff --git a/pkg/apis/proto/sourcetransform/v1/transform.proto b/pkg/apis/proto/sourcetransform/v1/sourcetransform.proto
similarity index 98%
rename from pkg/apis/proto/sourcetransform/v1/transform.proto
rename to pkg/apis/proto/sourcetransform/v1/sourcetransform.proto
index c2d0a7182e..b93d82b9a8 100644
--- a/pkg/apis/proto/sourcetransform/v1/transform.proto
+++ b/pkg/apis/proto/sourcetransform/v1/sourcetransform.proto
@@ -42,6 +42,7 @@ message SourceTransformRequest {
   bytes value = 2;
   google.protobuf.Timestamp event_time = 3;
   google.protobuf.Timestamp watermark = 4;
+  map<string, string> headers = 5;
 }
 
 /**
@@ -62,4 +63,4 @@ message SourceTransformResponse {
  */
 message ReadyResponse {
   bool ready = 1;
-}
\ No newline at end of file
+}