How to render boolean true in j2 file?

I’m not entirely sure if this is a YAML problem or an Ansible thing.

Trying to render a configuration json file from a j2 template.

Template.j2

{
“test”: {{ boolean_test }}
}

default.yml:

boolean_test: true

Result:

{
“test”: True
}

The result makes my node app complain (invalid json)

How to render

{
“test”: true
}

?

Found it:

default.yml:

boolean_test: !!str true