diff --git a/src/ol/source/bingmaps.js b/src/ol/source/bingmaps.js
index 1829ea5ec3..8c545a585c 100644
--- a/src/ol/source/bingmaps.js
+++ b/src/ol/source/bingmaps.js
@@ -85,7 +85,7 @@ ol.inherits(ol.source.BingMaps, ol.source.TileImage);
  */
 ol.source.BingMaps.TOS_ATTRIBUTION = new ol.Attribution({
   html: '<a class="ol-attribution-bing-tos" ' +
-      'href="http://www.microsoft.com/maps/product/terms.html">' +
+      'href="https://www.microsoft.com/maps/product/terms.html">' +
       'Terms of Use</a>'
 });
 
diff --git a/src/ol/source/stamen.js b/src/ol/source/stamen.js
index 098d441485..1beca37cd1 100644
--- a/src/ol/source/stamen.js
+++ b/src/ol/source/stamen.js
@@ -48,8 +48,8 @@ ol.inherits(ol.source.Stamen, ol.source.XYZ);
  */
 ol.source.Stamen.ATTRIBUTIONS = [
   new ol.Attribution({
-    html: 'Map tiles by <a href="http://stamen.com/">Stamen Design</a>, ' +
-        'under <a href="http://creativecommons.org/licenses/by/3.0/">CC BY' +
+    html: 'Map tiles by <a href="https://stamen.com/">Stamen Design</a>, ' +
+        'under <a href="https://creativecommons.org/licenses/by/3.0/">CC BY' +
         ' 3.0</a>.'
   }),
   ol.source.OSM.ATTRIBUTION