Tsc unknown compiler option allowNonTsExtensions

I am getting error TS5023: Unknown compiler option 'allowNonTsExtensions' when trying to run tsc on this project ionic start MyProject tutorial --v2.

Here is the tsconfig.json file provided by the tutorial.

  "compilerOptions": {
    "target": "ES5",
	"allowNonTsExtensions": true,
    "module": "commonjs",
    "sourceMap": true,
    "isolatedModules": true,
    "noEmitOnError": false,
    "rootDir": ".",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true
  "compileOnSave": false

Using typescript@1.6.2 globally in npm.

Out of curiosity since I’m still learning Ionic / Ionic 2 myself… Why are you running tsc against the project? As of the 2.0.0-alpha.23 release Webpack handles all that for you.

All you should need to do is after ionic start, go into the directory and run ionic serve.

We are using webstorm to work on our project and we are importing this tutorial into webstorm. For webstorm to get the imports in our Typescript correctly we have to enable a typescript compiler. When i enable the typescript compiler in webstorm and point it at the tsconfig file, webstorm complains about the "allowNonTsExtensions": true,.

So for testing purposes, i was running tsc external of webstorm to see if i could figure out what was going on. And tsc is giving me the same error.