Error building the package: ReactSlackChat.js Unexpected token (133:17)

[gazpachu]

➜  react-slack-chat git:(development) ✗ npm run build

> react-slack-chat@1.8.3 build /Users/blablabla/react-slack-chat
> cross-env NODE_ENV=production webpack

Hash: b4eb584c08a939d00a12
Version: webpack 1.15.0
Time: 115ms
   [0] multi main 28 bytes {0} [built] [1 error]
    + 1 hidden modules

ERROR in ./src/ReactSlackChat.js
Module parse failed: /Users/blablabla/react-slack-chat/src/ReactSlackChat.js Unexpected token (133:17)
You may need an appropriate loader to handle this file type.

Using node 8.9

[5punk]

have you polyfill'd?
are you using babel?

[gazpachu]

I'm using what package.json has in it. I'm talking about building the library, not importing it in my project.

UPDATED. Nevermind, now it seems to be working :-)