diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 2058a6e07..09f9d6bb4 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -116,6 +116,7 @@ sub thread_cleanup {
     *Slic3r::ExtrusionPath::DESTROY         = sub {};
     *Slic3r::ExtrusionPath::Collection::DESTROY = sub {};
     *Slic3r::Line::DESTROY                  = sub {};
+    *Slic3r::Object::XS::ZTable::DESTROY    = sub {};
     *Slic3r::Point::DESTROY                 = sub {};
     *Slic3r::Polygon::DESTROY               = sub {};
     *Slic3r::Polyline::DESTROY              = sub {};