diff --git a/libs/canvas/canvas/fwd.h b/libs/canvas/canvas/fwd.h
index 5e0d4df29f..f115654ae6 100644
--- a/libs/canvas/canvas/fwd.h
+++ b/libs/canvas/canvas/fwd.h
@@ -20,6 +20,7 @@
 #define __canvas_canvas_fwd_h__
 
 namespace ArdourCanvas {
+	class Arrow;
 	class Line;
 	class LineSet;
 	class Rectangle;