- url: 'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
- attribution: '© <a target="_parent" href="http://www.openstreetmap.org">OpenStreetMap</a> and contributors, under an <a target="_parent" href="http://www.openstreetmap.org/copyright">open license</a>'
+ url: document.location.protocol === 'https:' ?
+ 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png' :
+ 'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
+ attribution: '© <a href="http://www.openstreetmap.org/copyright" target="_blank">OpenStreetMap</a> contributors'