diff --git a/include/ircd/m/room/messages.h b/include/ircd/m/room/messages.h
index 999194690..b9a5b5575 100644
--- a/include/ircd/m/room/messages.h
+++ b/include/ircd/m/room/messages.h
@@ -57,6 +57,8 @@ struct ircd::m::room::messages
 	uint64_t depth() const;            // Available from the iterator key.
 	string_view state_root() const;    // Available from the iterator value.
 
+	explicit operator event::idx() const;
+
 	const m::event &fetch(std::nothrow_t);
 	const m::event &fetch();
 
diff --git a/ircd/m_room.cc b/ircd/m_room.cc
index fcb17ad1e..372518d96 100644
--- a/ircd/m_room.cc
+++ b/ircd/m_room.cc
@@ -1781,6 +1781,13 @@ catch(const db::not_found &e)
 	return false;
 }
 
+ircd::m::room::messages::operator
+ircd::m::event::idx()
+const
+{
+	return event_idx();
+}
+
 ircd::m::event::id::buf
 ircd::m::room::messages::event_id()
 const