diff --git a/LuaLibs/ProcessLapJoint.lua b/LuaLibs/ProcessLapJoint.lua
index 1e3e491..fed5992 100644
--- a/LuaLibs/ProcessLapJoint.lua
+++ b/LuaLibs/ProcessLapJoint.lua
@@ -5019,6 +5019,7 @@ function SawPlusChain.Saw.CalculateMachiningParameters( Proc)
    -- approccio e retrazione
    Cutting.LeadIn, Cutting.LeadOut = SawPlusChain.CalculateLeadInOut( Proc, Cutting)
    -- eventuale step orizzontale
+   Cutting.HorizontalSteps = {}
    if Cutting.Tool.SideStep then
       Cutting.HorizontalSteps = SawPlusChain.GetHorizontalSteps( Cutting)
    else