diff -r c2e0db52ea07 -r eae8b3bce545 src/linetypes/quadrilateral.h
--- a/src/linetypes/quadrilateral.h	Sun Mar 05 13:33:37 2017 +0200
+++ b/src/linetypes/quadrilateral.h	Sun Mar 05 16:47:52 2017 +0200
@@ -35,7 +35,7 @@
 	QString typeName() const override;
 
 protected:
-	friend class Model;
+	friend class ResourceVector<LDObject>;
 	LDQuadrilateral(Model* model);
 	LDQuadrilateral(const Vertex& v1, const Vertex& v2, const Vertex& v3, const Vertex& v4, Model* model = nullptr);
 };