diff --git a/event_schemas/OrderCreated.proto b/event_schemas/OrderCreated.proto
index b8f9f0d..7e46c30 100644
--- a/event_schemas/OrderCreated.proto
+++ b/event_schemas/OrderCreated.proto
@@ -5,7 +5,7 @@ package tutorial;
 import "google/protobuf/timestamp.proto";
 
 message OrderCreated {
-    required string order_id = 1;
+    required float order_id = 1;
     required string user_id = 2;
     required float total_amount = 3;
     required google.protobuf.Timestamp created_at = 4;