Browserify Plugin - Unable to catch errors

When using factor-bundle as a Browserify plugin, I'm unable to catch compilation errors.

``` javascript
return browserify({
entries: src.scripts
})
.ignore('jquery')
.plugin(factor, {
o: scriptDests
})
.bundle({
debug: true
})
.on('error', handleErrors)
.pipe(source(bundleFilename))
.pipe(gulp.dest(dev.scripts));
```

Which means my watch task fails :(.