error TS5037: Cannot compile external modules unless the '--module' flag is provided.

When I try to use the export keyword in Typescript, the ts file fails to transpile with the above referenced error.  If you install TypeScript in Visual Studio, the --module variable is set in the .csproj file.  I can't find anything in the file watcher dialog to set that variable.  When I installed the TypeScript file watcher I noticed there were a number of other typescript prefixed file watchers available.  Do I need to install one of them?