PhantomJS - 'unsafe-eval' is not an allowed source of script in the following Content Security Policy directive

Question

I'm trying to change the value of a input with PHP webdriver and PhantomJS. When I run a simple

$driver->executeScript("document.getElementById('changeme').value='".$newvalue."' ;", array());

I get the following error

Refused to evaluate a string as JavaScript because unsafe-eval is not an allowed source of script in the following Content Security Policy directive

I've got the following command line options set

--ignore-ssl-errors=true --web-security=false --ssl-protocol=any

Any suggestions?