axios incompatability - Cannot assign to read only property 'toJSON' of object 'Error'

[NodePing]

Heads up - new install today gives me this error:

TypeError: Cannot assign to read only property 'toJSON' of object 'Error' at Function.assign () at Object.inherits (/node_modules/axios/lib/utils.js:362:19)

axios just updated a bunch of things so it's likely the acme-client is using something they've deprecated.