diff --git a/xs/xsp/Surface.xsp b/xs/xsp/Surface.xsp
index b1128ac25..bc2367169 100644
--- a/xs/xsp/Surface.xsp
+++ b/xs/xsp/Surface.xsp
@@ -3,6 +3,7 @@
 %{
 #include <myinit.h>
 #include "Surface.hpp"
+#include "ClipperUtils.hpp"
 %}
 
 %name{Slic3r::Surface} class Surface {