diff --git a/src/exchangedb/plugin_exchangedb_postgres.c b/src/exchangedb/plugin_exchangedb_postgres.c
index d812f73e6..a259c7a0b 100644
--- a/src/exchangedb/plugin_exchangedb_postgres.c
+++ b/src/exchangedb/plugin_exchangedb_postgres.c
@@ -2944,6 +2944,7 @@ postgres_event_listen (void *cls,
 /**
  * Stop notifications.
  *
+ * @param cls the plugin's `struct PostgresClosure`
  * @param eh handle to unregister.
  */
 static void