diff --git a/Geo/Geo.cpp b/Geo/Geo.cpp
index 0b4c82746e4e03bc47c62d8eda7da4d66c39961f..f1e8918901dd46c35feaf713c64302f86de9f510 100644
--- a/Geo/Geo.cpp
+++ b/Geo/Geo.cpp
@@ -2705,6 +2705,12 @@ static void MaxNumSurface(void *a, void *b)
 
 static void ReplaceDuplicatePoints()
 {
+  // FIXME: This routine is in fact logically wrong (the
+  // compareTwoPoints function used in the avl tree is not a
+  // appropriate comparison function). The fix is simple (use a
+  // multi-d tree, e.g., MVertexOctree), but fixing the routine would
+  // break backward compatibility with old .geo files. This will be
+  // fixed in the new abstract GModel CAD creation routines.
   Vertex *v, **pv, **pv2;
   Curve *c;
   Surface *s;