diff --git a/libs/ardour/ardour/vbap.h b/libs/ardour/ardour/vbap.h
index 063bcb82d6..419930c574 100644
--- a/libs/ardour/ardour/vbap.h
+++ b/libs/ardour/ardour/vbap.h
@@ -63,7 +63,6 @@ private:
 	void compute_gains (double g[3], int ls[3], int azi, int ele);
 
 	void update ();
-	void mark_dirty ();
 };
 
 } /* namespace */