diff --git a/libs/ardour/ardour/file_source.h b/libs/ardour/ardour/file_source.h
index 5898d04f0a..3d9c8c623f 100644
--- a/libs/ardour/ardour/file_source.h
+++ b/libs/ardour/ardour/file_source.h
@@ -74,6 +74,7 @@ public:
 
 	void inc_use_count ();
 	bool removable () const;
+        bool is_stub () const;
 
 	const std::string& origin() const { return _origin; }