diff --git a/include/ircd/m/event.h b/include/ircd/m/event.h
index 65f6bd93d..3b6797c42 100644
--- a/include/ircd/m/event.h
+++ b/include/ircd/m/event.h
@@ -148,6 +148,7 @@ struct ircd::m::event::conforms
 
 	void set(const code &code);
 	void del(const code &code);
+	void operator|=(const code &) &;
 
 	conforms() = default;
 	conforms(const event &);
diff --git a/ircd/m/event.cc b/ircd/m/event.cc
index d76ba6818..0d7e2383c 100644
--- a/ircd/m/event.cc
+++ b/ircd/m/event.cc
@@ -650,6 +650,13 @@ ircd::m::event::conforms::conforms(const event &e)
 			set(DEPTH_ZERO);
 }
 
+void
+ircd::m::event::conforms::operator|=(const code &code)
+&
+{
+	set(code);
+}
+
 void
 ircd::m::event::conforms::del(const code &code)
 {