diff --git a/libs/canvas/canvas/debug.h b/libs/canvas/canvas/debug.h
index e001e28cd1..6f639d1e09 100644
--- a/libs/canvas/canvas/debug.h
+++ b/libs/canvas/canvas/debug.h
@@ -32,6 +32,8 @@ namespace PBD {
 		LIBCANVAS_API extern DebugBits CanvasEvents;
 		LIBCANVAS_API extern DebugBits CanvasRender;
 		LIBCANVAS_API extern DebugBits CanvasEnterLeave;
+		LIBCANVAS_API extern DebugBits CanvasBox;
+		LIBCANVAS_API extern DebugBits CanvasSizeAllocate;
 	}
 }
 
diff --git a/libs/canvas/debug.cc b/libs/canvas/debug.cc
index 84dc1a8a45..0a44fefe2b 100644
--- a/libs/canvas/debug.cc
+++ b/libs/canvas/debug.cc
@@ -30,6 +30,8 @@ PBD::DebugBits PBD::DEBUG::CanvasItemsDirtied = PBD::new_debug_bit ("canvasitems
 PBD::DebugBits PBD::DEBUG::CanvasEvents = PBD::new_debug_bit ("canvasevents");
 PBD::DebugBits PBD::DEBUG::CanvasRender = PBD::new_debug_bit ("canvasrender");
 PBD::DebugBits PBD::DEBUG::CanvasEnterLeave = PBD::new_debug_bit ("canvasenterleave");
+PBD::DebugBits PBD::DEBUG::CanvasBox = PBD::new_debug_bit ("canvasbox");
+PBD::DebugBits PBD::DEBUG::CanvasSizeAllocate = PBD::new_debug_bit ("canvassizeallocate");
 
 struct timeval ArdourCanvas::epoch;
 map<string, struct timeval> ArdourCanvas::last_time;