141,144c141,144
<                 // add mscorlib
<                 state.ClrModule.AddReferenceByName(typeof(string).Assembly.FullName);
<                 // add system.dll
<                 state.ClrModule.AddReferenceByName(typeof(System.Diagnostics.Debug).Assembly.FullName);
---
>                 if (state.EngineOptions.AutoReferenceMscorlib)
>                     state.ClrModule.AddReferenceByName(typeof(string).Assembly.FullName);
>                 if (state.EngineOptions.AutoReferenceSystem)
>                     state.ClrModule.AddReferenceByName(typeof(System.Diagnostics.Debug).Assembly.FullName);