diff --git a/libs/ardour/ardour/file_source.h b/libs/ardour/ardour/file_source.h
index 6991840beb..8fe3ab21da 100644
--- a/libs/ardour/ardour/file_source.h
+++ b/libs/ardour/ardour/file_source.h
@@ -84,6 +84,8 @@ public:
 
 	virtual void prevent_deletion ();
 
+	virtual void prevent_deletion ();
+
 protected:
 	FileSource (Session& session, DataType type,
 	            const std::string& path,