diff --git a/changelog.d/9057.doc b/changelog.d/9057.doc
new file mode 100644
index 000000000000..d16686e7dcdb
--- /dev/null
+++ b/changelog.d/9057.doc
@@ -0,0 +1 @@
+Add missing user_mapping_provider configuration to the Keycloak OIDC example. Contributed by @chris-ruecker.
diff --git a/docs/openid.md b/docs/openid.md
index da391f74aa0e..ffa4238fff50 100644
--- a/docs/openid.md
+++ b/docs/openid.md
@@ -158,6 +158,10 @@ oidc_config:
    client_id: "synapse"
    client_secret: "copy secret generated from above"
    scopes: ["openid", "profile"]
+   user_mapping_provider:
+     config:
+       localpart_template: "{{ user.preferred_username }}"
+       display_name_template: "{{ user.name }}"
 ```
 ### [Auth0][auth0]