Split off from https://github.com/nodejs/node/issues/5344#issuecomment-281392069. ```js 'use strict'; const vm = require('vm'); const ctx = vm.createContext({ x: 42 }); try { const result = vm.runInContext('"use strict"; x = 1', ctx); } catch(e) { console.log(e.stack); console.log('x is', ctx.x) } ```