diff --git a/api/server-server/backfill.yaml b/api/server-server/backfill.yaml
index e98c9e90..4bf62663 100644
--- a/api/server-server/backfill.yaml
+++ b/api/server-server/backfill.yaml
@@ -33,7 +33,7 @@ paths:
       description: |-
         Retrieves a sliding-window history of previous PDUs that occurred in the given room.
         Starting from the PDU ID(s) given in the ``v`` argument, the PDUs given in ``v`` and
-        the PDUs that preceded it are retrieved, up to the total number given by the ``limit``.
+        the PDUs that preceded them are retrieved, up to the total number given by the ``limit``.
       operationId: backfillRoom
       security:
         - signedRequest: []