diff --git a/src/RhinoInside.Revit.GH/Components/Structure/AddAnalyticalPanelByExtrusion.cs b/src/RhinoInside.Revit.GH/Components/Structure/AddAnalyticalPanelByExtrusion.cs
index 1712282a7..6c6e254d4 100644
--- a/src/RhinoInside.Revit.GH/Components/Structure/AddAnalyticalPanelByExtrusion.cs
+++ b/src/RhinoInside.Revit.GH/Components/Structure/AddAnalyticalPanelByExtrusion.cs
@@ -177,7 +177,7 @@ double height
 
       // Curve
       var curveLoop = analyticalPanel.GetOuterContour().ToPolyCurve();
-      var currentCurve = Curve.ProjectToPlane(curveLoop, plane).GetSubCurves();
+      var currentCurve = Curve.ProjectToPlane(curveLoop, plane).DuplicateSegments();
 
       if (currentCurve is null)
         return false;