diff --git a/protos/inter_container.proto b/protos/inter_container.proto
index ac2af4f..4d4ffe8 100644
--- a/protos/inter_container.proto
+++ b/protos/inter_container.proto
@@ -48,7 +48,8 @@
     MessageType type = 2;
     string from_topic = 3;
     string to_topic = 4;
-    int64 timestamp = 5;
+    string key_topic = 5;
+    int64 timestamp = 6;
 }
 
 message Argument {