diff --git a/changelog.d/13443.doc b/changelog.d/13443.doc
new file mode 100644
index 000000000000..0db5d1b3b4ed
--- /dev/null
+++ b/changelog.d/13443.doc
@@ -0,0 +1 @@
+Update documentation for config setting `macaroon_secret_key`.
\ No newline at end of file
diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index 2e2e59195bd0..3a9466a83770 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -2495,9 +2495,13 @@ track_appservice_user_ips: true
 ---
 ### `macaroon_secret_key`
 
-A secret which is used to sign access tokens. If none is specified,
-the `registration_shared_secret` is used, if one is given; otherwise,
-a secret key is derived from the signing key.
+A secret which is used to sign
+- access token for guest users,
+- short-term login token used during SSO logins (OIDC or SAML2) and
+- token used for unsubscribing from email notifications.
+
+If none is specified, the `registration_shared_secret` is used, if one is given;
+otherwise, a secret key is derived from the signing key.
 
 Example configuration:
 ```yaml