diff --git a/xs/xsp/TriangleMesh.xsp b/xs/xsp/TriangleMesh.xsp
index 95f2f7d52f..edfb4a1980 100644
--- a/xs/xsp/TriangleMesh.xsp
+++ b/xs/xsp/TriangleMesh.xsp
@@ -185,7 +185,7 @@ TriangleMesh::slice(z)
         
         std::vector<ExPolygons> layers;
         TriangleMeshSlicer mslicer(THIS);
-        mslicer.slice(z_f, &layers, [](){});
+        mslicer.slice(z_f, 0.049f, &layers, [](){});
         
         AV* layers_av = newAV();
         size_t len = layers.size();