diff --git a/LuaLibs/ProcessLapJoint.lua b/LuaLibs/ProcessLapJoint.lua
index 6ad89a2..f6abc40 100644
--- a/LuaLibs/ProcessLapJoint.lua
+++ b/LuaLibs/ProcessLapJoint.lua
@@ -3503,7 +3503,7 @@ local function MakeByPockets( Proc, nPhase, nRawId, nPartId, nChamfer, dDepthCha
       -- se tre facce aumento il diametro di quanto possibile
       elseif Proc.Fct == 3 then
          local nFacInd = BL.GetFaceWithMostAdj( Proc.Id, nPartId, false)
-         local dWidth = GetUShapeWidth( Proc, nFacInd or -1)
+         local dWidth = GetUShapeWidth( Proc, nFacInd or -1) or dDimMin
          if dWidth > dDimMin then
             dDimMin = min( 2 * dDimMin, dWidth)
          end