Object spread operator requires specified objectAssign option with \'Object.assign\' or polyfill helper.

How do I make the following work with buble from the command line?

$ echo 'console.log({ ...{ a: 1, b : 2 } });' | babel | node
{ a: 1, b: 2 }

$ echo 'console.log({ ...{ a: 1, b : 2 } });' | buble | node

/tmp/node_modules/buble/dist/buble.deps.js:10328
  				throw new CompileError( this, 'Object spread operator requires specified objectAssign option with \'Object.assign\' or polyfill helper.' );
  				^