diff --git a/src/ViewportWidget.cpp b/src/ViewportWidget.cpp
index f46d0d2..7079435 100644
--- a/src/ViewportWidget.cpp
+++ b/src/ViewportWidget.cpp
@@ -35,6 +35,7 @@
 #include <QtMath>
 #include <ElCLib.hxx>
 #include <gp_Pnt2d.hxx>
+#include <gp_Vec.hxx>
 #include <QOpenGLShaderProgram>
 #include <QVector>
 #include <map>
@@ -574,14 +575,14 @@ void ViewportWidget::drawSketch(const SketchFeature* sketch)
             const auto& p1_3d = rect->corner1();
             const auto& p3_3d = rect->corner2();
 
-            gp_Pnt2d p1_2d = ElCLib::To2d(p1_3d, plane);
-            gp_Pnt2d p3_2d = ElCLib::To2d(p3_3d, plane);
+            gp_Pnt2d p1_2d(gp_Vec(plane.Location(), p1_3d).Dot(plane.XDirection()), gp_Vec(plane.Location(), p1_3d).Dot(plane.YDirection()));
+            gp_Pnt2d p3_2d(gp_Vec(plane.Location(), p3_3d).Dot(plane.XDirection()), gp_Vec(plane.Location(), p3_3d).Dot(plane.YDirection()));
 
             gp_Pnt2d p2_2d(p3_2d.X(), p1_2d.Y());
             gp_Pnt2d p4_2d(p1_2d.X(), p3_2d.Y());
 
-            gp_Pnt p2_3d = ElCLib::To3d(p2_2d, plane);
-            gp_Pnt p4_3d = ElCLib::To3d(p4_2d, plane);
+            gp_Pnt p2_3d = ElCLib::To3d(plane, p2_2d);
+            gp_Pnt p4_3d = ElCLib::To3d(plane, p4_2d);
 
             lineVertices << p1_3d.X() << p1_3d.Y() << p1_3d.Z();
             lineVertices << p2_3d.X() << p2_3d.Y() << p2_3d.Z();