diff --git a/src/libslic3r/libslic3r.h b/src/libslic3r/libslic3r.h
index 2f7932a4e..e3816b87f 100644
--- a/src/libslic3r/libslic3r.h
+++ b/src/libslic3r/libslic3r.h
@@ -26,7 +26,7 @@
 // Saves around 32% RAM after slicing step, 6.7% after G-code export (tested on PrusaSlicer 2.2.0 final).
 using coord_t = int32_t;
 #else
-//FIXME At least FillRectilinear2 requires coord_t to be 32bit.
+//FIXME At least FillRectilinear2 and std::boost Voronoi require coord_t to be 32bit.
 typedef int64_t coord_t;
 #endif
 
diff --git a/xs/xsp/Geometry.xsp b/xs/xsp/Geometry.xsp
index 5d6454e8a..e44d16949 100644
--- a/xs/xsp/Geometry.xsp
+++ b/xs/xsp/Geometry.xsp
@@ -13,7 +13,7 @@ Pointfs arrange(size_t total_parts, Vec2d* part, coordf_t dist, BoundingBoxf* bb
     %code{% 
         Pointfs points;
         if (! Slic3r::Geometry::arrange(total_parts, *part, dist, bb, points))
-            CONFESS(PRINTF_ZU " parts won't fit in your print area!\n", total_parts);
+            CONFESS("%zu parts won't fit in your print area!\n", total_parts);
         RETVAL = points;
     %};