diff --git a/specs/waku/v2/waku-message.md b/specs/waku/v2/waku-message.md
index 37ab8fbc..699bd3d5 100644
--- a/specs/waku/v2/waku-message.md
+++ b/specs/waku/v2/waku-message.md
@@ -49,7 +49,7 @@ The `version` field MAY be filled out to allow for various types of payload encr
 message WakuMessage {
   optional bytes payload = 1;
   optional fixed32 contentTopic = 2;
-  optional string version = 3;
+  optional uint32 version = 3;
 }
 ```