diff --git a/TODO.txt b/TODO.txt
index 3f673083..8e138df4 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -4,6 +4,7 @@ BUGS
 o Some invalid DXF data gets pass the import checks and breaks the tessing code
 o Broken polyhedron() entities are not correctly detected and cause CGAL segfaults
 o Tesselation via GLU sometimes produces strange results
+o Non-manifold objects make CGAL crash (e.g. two cubes which touch at one edge)
 
 USER INTERFACE
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