diff --git a/src/kiri/mode/cam/op-trace.js b/src/kiri/mode/cam/op-trace.js
index 6ec46dba..f8a937bf 100644
--- a/src/kiri/mode/cam/op-trace.js
+++ b/src/kiri/mode/cam/op-trace.js
@@ -89,6 +89,7 @@ class OpTrace extends CamOp {
             if (reContour) {
                 state.contourPolys(widget, slice.camLines);
             }
+            POLY.setWinding(slice.camLines, cutdir, false);
             slice.output()
                 .setLayer("trace follow", {line: color}, false)
                 .addPolys(slice.camLines)