Google Fonts Mixed Content Error

Hi, this is quite a nice plugin but it seems to throw an error when Google Fonts are used:

“Mixed Content: The page at ‘https://mydomain.com’ was loaded over HTTPS, but requested an insecure stylesheet ‘https://fonts.googleapis.com/css?family=Titillium+Web%3Anormal&subset=latin&ver=5.2.2’. This request has been blocked; the content must be served over HTTPS.”