Index: geometry.c
--- geometry.c.orig
+++ geometry.c
@@ -615,7 +615,7 @@ int boxes_2d_intersect_p(BOX_2D * a, BOX_2D * b)
     return 1;
 }
 
-int boxes_3d_intersect_p(BOX_2D * a, BOX_2D * b)
+int boxes_3d_intersect_p(BOX_3D * a, BOX_3D * b)
 {
     if (a->max[X] < b->min[X])	// a left of b
 	return 0;