Index: geometry.h
--- geometry.h.orig
+++ geometry.h
@@ -237,7 +237,7 @@ void fold_min_max_polyline_3d(BOX_3D * b, POLYLINE_3D 
 void copy_box_2d(BOX_2D * r, BOX_2D * s);
 void copy_box_3d(BOX_3D * r, BOX_3D * s);
 int boxes_2d_intersect_p(BOX_2D * a, BOX_2D * b);
-int boxes_3d_intersect_p(BOX_2D * a, BOX_2D * b);
+int boxes_3d_intersect_p(BOX_3D * a, BOX_3D * b);
 
 // ---- transformations --------------------------------------------------------