process.send is not a function in child spawned with babel-node (ipc doesn't work)

Input Code

spawn.js:

import {spawn} from 'child_process'

spawn('babel-node', ['child.js'], {
  stdio: [0, 1, 2, 'ipc']
})

child.js:

process.send({hello: 'world'})

Babel Configuration (.bablerc, package.json, cli command)

{
  "presets": ["es2015", "stage-1"]
}

Expected Behavior

No errors are thrown when I spawn child.js with node.

Current Behavior

When I spawn child.js with babel-node, I see the following error in the console:

child.js:3
process.send({ hello: 'world' });
        ^

TypeError: process.send is not a function
    at Object.<anonymous> (/Users/andy/smart-restart/child.js:1:9)
    at Module._compile (module.js:413:34)
    at loader (/Users/andy/.nvm/versions/node/v5.12.0/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:146:5)
    at Object.require.extensions.(anonymous function) [as .js] (/Users/andy/.nvm/versions/node/v5.12.0/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:156:7)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at /Users/andy/.nvm/versions/node/v5.12.0/lib/node_modules/babel-cli/lib/_babel-node.js:151:24
    at Object.<anonymous> (/Users/andy/.nvm/versions/node/v5.12.0/lib/node_modules/babel-cli/lib/_babel-node.js:152:7)
    at Module._compile (module.js:413:34)

Context

I’m the author of smart-restart. I’m trying to get it to work when spawning the supervised process with babel-node.

Your Environment