Using slider in composite styling

When adding a slider to a composite type property I am getting the following error (when trying to change value of slider):

InputNumber.js?d43d:244 Uncaught SyntaxError: Invalid regular expression: /^initial|inherit/: Stack overflow at child.validateInputValue (InputNumber.js?d43d:244) at child.parseValue (PropertyInteger.js?83a3:40) at child.valueOnIndex (PropertyCompositeView.js?8ca1:122) at customValue (PropertyCompositeView.js?8ca1:88) at child.getTargetValue (PropertyView.js?aa5b:274) at child.targetUpdated (PropertyView.js?aa5b:194) at executeBound (underscore.js?17fb:762) at child.eval (underscore.js?17fb:775) at child.eval (underscore.js?17fb:122) at triggerEvents (backbone.js?ab5c:369)

The line in the code that it fails on:

        // If the value is one of the fixed values I leave it as it is
        var regFixed = new RegExp('^' + fixed.join('|'), 'g');
        if (fixed.length && regFixed.test(val)) {

Is there a solution for this?