diff --git a/cameo/README b/cameo/README
index 4d8ce38..7567c8e 100644
--- a/cameo/README
+++ b/cameo/README
@@ -159,6 +159,9 @@ Area clearing:
 
   area <overlap>
 
+WARNING: sometimes produces inaccurate results with toolpaths that eat
+into the workpiece. Always check the toolpath before machining !
+
 Generate toolpaths to mill (remove) the area enclosed by the current
 path. If there are multiple paths, the area in the outermost is removed
 but the areas covered by enclosed paths are left intact. If they contain