diff --git a/Lua_Trimming.cpp b/Lua_Trimming.cpp
index afb8451..31d13dd 100644
--- a/Lua_Trimming.cpp
+++ b/Lua_Trimming.cpp
@@ -377,6 +377,7 @@ LuaRegolarizeSurfaceLocally( lua_State* L)
    LuaCheckParam( L, 5, dLinTol)
    int nType = 0 ;
    LuaCheckParam( L, 6, nType)
+   LuaClearStack( L) ;
 
    int nId = ExeRegolarizeSurfaceLocally( nParentId, nSurfId, nSyncStartId, nSyncEndId, dLinTol, nType) ;
    LuaSetParam( L, nId) ;