diff --git a/LuaLibs/WProcessFreeContour.lua b/LuaLibs/WProcessFreeContour.lua
index f49eb8e..10d2512 100644
--- a/LuaLibs/WProcessFreeContour.lua
+++ b/LuaLibs/WProcessFreeContour.lua
@@ -2406,7 +2406,7 @@ local function MakeByPocket( Proc, nRawId, b3Raw)
       local nAddedBottomSurface = EgtSurfTmByFlatContour( nAddGrpId, nBottomLoopId)
       local vtNAddedBottomSurface = EgtSurfTmFacetNormVersor( nAddedBottomSurface, 0)
       if AreOppositeVectorApprox( vtNAddedBottomSurface, Z_AX()) then EgtInvertSurf( nAddedBottomSurface) end
-      nProcTmWithAddedBottomSurfaceId = EgtSurfTmBySewing( nAddGrpId, { nAddedBottomSurface, Proc.Id})
+      nProcTmWithAddedBottomSurfaceId = EgtSurfTmBySewing( nAddGrpId, { nAddedBottomSurface, Proc.Id}, false)
       if nProcTmWithAddedBottomSurfaceId then
          -- ricerco la faccia di fondo della trimesh (gli id potrebbero essere cambiati)
          for i = 1, Proc.Fct do