diff --git a/LuaLibs/CalcPaths.lua b/LuaLibs/CalcPaths.lua
index e6df65a..f2a7f55 100644
--- a/LuaLibs/CalcPaths.lua
+++ b/LuaLibs/CalcPaths.lua
@@ -3509,7 +3509,7 @@ end
 --------------------------------------------------------------------
 local function UpdateTrimSurfWithExtraShell( nSrf, nCrv, dStrand, nGrpId)
    
-   local nSrfExtraShell = EgtSurfFrFatCurve( nGrpId, nCrv, dStrand * 0.5 + s_dOffsCorr * 0.5, true)
+   local nSrfExtraShell = EgtSurfFrFatCurve( nGrpId, nCrv, dStrand * 0.5 + s_dOffsCorr * 0.5, true, false)
    if nSrfExtraShell then
       if not EgtSurfFrSubtract( nSrf, nSrfExtraShell) then
          EgtOutLog( 'Error : EgtSurfFrSubtract with ExtraShell for TotTrimSurfRegion failed (layer '.. EgtNumToString( s_nCurrIdx) ..') - CalcPaths')