Write log messages to stderr only

I'm writing a command line app, and evaluated Winston for logging for its breadth of out-of-the-box transports.

I saw in the console transport that some log messages are written to stdout.

I'm writing program output (ie: the final results of my command line app) to stdout. This is pretty common Unix-ish stuff.

The output of my program can be piped into the input of another program (more Unix-ish stuff), or used as an argument to another program (if it doesn't handle stdin).

I can't use the output of my program (stdout) if stdout is also being used for diagnostic (ie: logging) output.

Ideally, diagnostic info like logging (as well as errors) should be confined to stderr so that stdout can be used for program output.