diff --git a/src/service/globals/mod.rs b/src/service/globals/mod.rs
index 44a22166..1f90684f 100644
--- a/src/service/globals/mod.rs
+++ b/src/service/globals/mod.rs
@@ -442,7 +442,8 @@ impl Service<'_> {
         room_versions
     }
 
-    /// TODO: the key valid until timestamp is only honored in room version > 4
+    /// TODO: the key valid until timestamp (`valid_until_ts`) is only honored in room version > 4
+    ///
     /// Remove the outdated keys and insert the new ones.
     ///
     /// This doesn't actually check that the keys provided are newer than the old set.