<!-- Thank you for contributing to TypeScript! Please review this checklist before submitting your issue. [ ] Many common issues and suggestions are addressed in the FAQ https://github.com/Microsoft/TypeScript/wiki/FAQ [ ] Search for duplicates before logging new issues https://github.com/Microsoft/TypeScript/issues?utf8=%E2%9C%93&q=is%3Aissue [ ] Questions are best asked and answered at Stack Overflow http://stackoverflow.com/questions/tagged/typescript For bug reports, please include the information below. __________________________________________________________ --> **TypeScript Version:** nightly (1.9.0-dev.20160604-1.0) **Code** ``` ts let foo:number|null = 0; switch(foo) { case null: break; case 0: console.log('bar'); } ``` **Expected behavior:** Null check should be allowed **Actual behavior:** Compiler complains "TypeScript Type 'null' is not comparable to type 'number'. (TS2678)" **Note:** If I add an 'if' condition before the switch, the compiler does not complain about either the 'if' or the switch. For instance: ``` ts let foo:number|null = 0; if (foo === null) { console.log('bar'); } switch(foo) { case null: break; case 0: console.log('bar'); } ```