1 files changed, 1 insertions, 0 deletions
diff --git a/libs/canvas/canvas/fwd.h b/libs/canvas/canvas/fwd.h
index 1e812f9144..b8242e86bb 100644
--- a/libs/canvas/canvas/fwd.h
+++ b/libs/canvas/canvas/fwd.h
@@ -24,6 +24,7 @@
 namespace ArdourCanvas {
 	class WaveView;
 	class Line;
+        class LineSet;
 	class Rectangle;
 	class Polygon;
 	class PolyLine;