diff --git a/CSG.Sharp.Lib/Primitives/Node.cs b/CSG.Sharp.Lib/Primitives/Node.cs
index d6dc319..fc682ce 100644
--- a/CSG.Sharp.Lib/Primitives/Node.cs
+++ b/CSG.Sharp.Lib/Primitives/Node.cs
@@ -71,7 +71,7 @@ public IList<Polygon> ClipPolygons(IList<Polygon> polygons)
             if (_back != null) back = _back.ClipPolygons(back).ToList();
             else back = Enumerable.Empty<Polygon>().ToList();
 
-            return front.Concat(back).ToArray();
+            return front.Concat(back).ToList();
         }
 
         // Remove all polygons in this BSP tree that are inside the other BSP tree
@@ -118,4 +118,4 @@ public void Build(IList<Polygon> polygons)
             }
         }
     }
-}
\ No newline at end of file
+}