diff --git a/changelog.d/16628.doc b/changelog.d/16628.doc
new file mode 100644
index 000000000000..4dd1e4874e9e
--- /dev/null
+++ b/changelog.d/16628.doc
@@ -0,0 +1 @@
+Note that the option [`outbound_federation_restricted_to`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#outbound_federation_restricted_to) was added in Synapse 1.89.0, and fix a nearby formatting error.
diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index a673975e0411..4200e70c8383 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -4219,6 +4219,9 @@ outbound_federation_restricted_to:
 Also see the [worker
 documentation](../../workers.md#restrict-outbound-federation-traffic-to-a-specific-set-of-workers)
 for more info.
+
+_Added in Synapse 1.89.0._
+
 ---
 ### `run_background_tasks_on`