diff --git a/src/backend/session/direct.rs b/src/backend/session/direct.rs
index 1385fbd..9d0958a 100644
--- a/src/backend/session/direct.rs
+++ b/src/backend/session/direct.rs
@@ -322,6 +322,7 @@ impl Drop for DirectSession {
     }
 }
 
+/// Ids of registered `SessionObserver`s of the `DirectSessionNotifier`
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct Id(usize);