How to tell IDEA that files are JSON?

I am trying to make IDEA parse/format *.jsb2 files as JSON.

Unfortunately it seems that handling *.json is hardcoded?!

*.json is assigned to the "JavaScript files" file type. However if I assign *.jsb2 to that file type, too, then IDEA shows errors, because naturally the file does not contain complete JavaScript code, but a single object literal.

Should I create an issue or is there something I missed?