diff --git a/LuaLibs/BeamLib.lua b/LuaLibs/BeamLib.lua
index 774df0e..6843fe6 100644
--- a/LuaLibs/BeamLib.lua
+++ b/LuaLibs/BeamLib.lua
@@ -843,7 +843,7 @@ function BeamLib.GetTunnelDimension( Proc, nPartId)
    local b3BoxLoc = EgtGetBBoxRef( Proc.Id, GDB_BB.STANDARD, frFc)
    local dDepth = b3BoxLoc:getDimZ()
    -- recupero gruppo per geometria addizionale
-   local nAddGrpId = BL.GetAddGroup( nPartId)
+   local nAddGrpId = BeamLib.GetAddGroup( nPartId)
    if not nAddGrpId then
       EgtOutLog( 'Error : missing AddGroup')
       return 0, 0, 0