diff --git a/changelogs/client_server/newsfragments/2407.clarification b/changelogs/client_server/newsfragments/2407.clarification
new file mode 100644
index 00000000..1bc654e8
--- /dev/null
+++ b/changelogs/client_server/newsfragments/2407.clarification
@@ -0,0 +1 @@
+Add further normative language in mutual rooms server behaviour.
diff --git a/content/client-server-api/modules/mutual_rooms.md b/content/client-server-api/modules/mutual_rooms.md
index 162e9c71..511f1573 100644
--- a/content/client-server-api/modules/mutual_rooms.md
+++ b/content/client-server-api/modules/mutual_rooms.md
@@ -6,9 +6,9 @@
 
 #### Server behaviour
 
-The server may decide that the response to this endpoint is too large, and only return a
-subset of the results. In this case, the server should populate the optional field `next_batch`
-with an [opaque identifier](/appendices/#opaque-identifiers). The client may then supply
+The server MAY decide that the response to this endpoint is too large, and only return a
+subset of the results. In this case, the server populates the optional field `next_batch`
+with an [opaque identifier](/appendices/#opaque-identifiers). The client can then supply
 the identifier as the `from` query parameter in a subsequent request, along with the original
 `user_id`, to fetch the next batch of responses. This will continue until the server no longer
 inserts `next_batch`, meaning there are no further results.