I tested my site via Pingdom and got this:

I searched but couldn\'t fi
A fairly easy workaround would be to generate your own kit with Font Squirrel's Webfont Generator:
https://www.fontsquirrel.com/tools/webfont-generator
To be able to use this, you would need to download the fonts (Montserrat and Open Sans are both available on Font Squirrel) and add them to the generator. This can be used for adding further customization. (I've used it many times in cases where the font in Google Webfonts didn't have the necessary subsetting for Hungarian language even though it was available in the original font.)