diff --git a/lib/client.js b/lib/client.js
index bfb4efad8..a05bd70fc 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -77,7 +77,10 @@ var OLM_ALGORITHM = "m.olm.v1.curve25519-aes-sha2";
  *    in end-to-end crypto. If not specified, end-to-end crypto will be disabled.
  *
  * @param {Object=} opts.sessionStore A store to be used for end-to-end crypto
- *    session data. If not specified, end-to-end crypto will be disabled.
+ *    session data. This should be a {@link
+ *    module:store/session/webstorage~WebStorageSessionStore|WebStorageSessionStore},
+ *    or an object implementing the same interface. If not specified,
+ *    end-to-end crypto will be disabled.
  *
  * @param {Object} opts.scheduler Optional. The scheduler to use. If not
  * specified, this client will not retry requests on failure. This client