diff --git a/src/mesh/api.js b/src/mesh/api.js
index 2d17c4b1..0b896c8d 100644
--- a/src/mesh/api.js
+++ b/src/mesh/api.js
@@ -133,7 +133,7 @@ let selection = {
         }
         // prevent selection of model and its group
         let mgsel = selected.filter(s => s instanceof mesh.model).map(m => m.group);
-        selected = selected.filter(sel => !mgsel.contains(sel));
+        selected = selected.filter(sel => !mgsel.contains(sel)).filter(v => v);
         // highlight selected
         for (let object of selected) {
             object.select(true);