diff --git a/libs/ardour/slave.cc b/libs/ardour/slave.cc
index 8f152e2b08..65a25ec3ab 100644
--- a/libs/ardour/slave.cc
+++ b/libs/ardour/slave.cc
@@ -72,3 +72,4 @@ SlaveSessionProxy::sample_time() const
 	return session.engine().sample_time();
 }
 
+} // namespace ARDOUR