diff --git a/content/docs/rfcs/13/README.md b/content/docs/rfcs/13/README.md
index 3e830c63..caf6ce03 100644
--- a/content/docs/rfcs/13/README.md
+++ b/content/docs/rfcs/13/README.md
@@ -72,7 +72,10 @@ import "waku/message/v1/message.proto";
 
 message WakuMessageKeyValue {
   optional bytes message_hash = 1; // Globally unique key for a Waku Message
-  optional waku.message.v1.WakuMessage message = 2; // Full message content as value
+
+  // Full message content and associated pubsub_topic as value
+  optional waku.message.v1.WakuMessage message = 2;
+  optional string pubsub_topic = 3;
 }
 
 message StoreQueryRequest {
@@ -110,13 +113,17 @@ message StoreQueryResponse {
 ### Waku message key-value pairs
 
 The store query protocol operates as a query protocol for a key-value store of historical Waku messages,
-with each entry having a [14/WAKU2-MESSAGE](https://rfc.vac.dev/spec/14/) as value
+with each entry having a [14/WAKU2-MESSAGE](https://rfc.vac.dev/spec/14/) and associated pubsub topic as value,
 and [deterministic message hash](https://rfc.vac.dev/spec/14/#deterministic-message-hashing) as key.
 The store can be queried to return either a set of keys or a set of key-value pairs.
 Within the store query protocol, Waku message keys and values MUST be represented in a `WakuMessageKeyValue` message.
 This message MUST contain the deterministic `message_hash` as key.
-It MAY contain the full `WakuMessage` as value in the `message` field,
+It MAY contain the full `WakuMessage` and associated pubsub topic as value in the `message` and `pubsub_topic` fields,
 depending on the use case as set out below.
+If the message contains a value entry in addition to the key,
+both the `message` and `pubsub_topic` fields MUST be populated.
+The message MUST NOT have either `message` or `pubsub_topic` populated with the other unset.
+Both fields MUST either be set or unset.
 
 ### Waku message store eligibility