diff --git a/src/core/PaperScript.js b/src/core/PaperScript.js
index 152ded69..aecc290f 100644
--- a/src/core/PaperScript.js
+++ b/src/core/PaperScript.js
@@ -323,7 +323,7 @@ Base.exports.PaperScript = function() {
 
         // Source-map support:
         // Encodes a Variable Length Quantity as a Base64 string.
-        // See: http://www.html5rocks.com/en/tutorials/developertools/sourcemaps
+        // See: https://www.html5rocks.com/en/tutorials/developertools/sourcemaps/
         function encodeVLQ(value) {
             var res = '',
                 base64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
diff --git a/src/paper.js b/src/paper.js
index f2c6d327..f5387440 100644
--- a/src/paper.js
+++ b/src/paper.js
@@ -23,7 +23,7 @@
  ***
  *
  * Acorn.js
- * http://marijnhaverbeke.nl/acorn/
+ * https://marijnhaverbeke.nl/acorn/
  *
  * Acorn is a tiny, fast JavaScript parser written in JavaScript,
  * created by Marijn Haverbeke and released under an MIT license.
diff --git a/src/path/Curve.js b/src/path/Curve.js
index 1c5b6714..6ec86979 100644
--- a/src/path/Curve.js
+++ b/src/path/Curve.js
@@ -1476,7 +1476,7 @@ new function() { // Scope for methods that require private functions
             // 2: normal, 1st derivative
             // 3: curvature, 1st derivative & 2nd derivative
             // Prevent tangents and normals of length 0:
-            // http://stackoverflow.com/questions/10506868/
+            // https://stackoverflow.com/questions/10506868/
             if (t < tMin) {
                 x = cx;
                 y = cy;
@@ -1698,7 +1698,7 @@ new function() { // Scope for methods that require private functions
          * Peaks are locations sharing some qualities of curvature extrema but
          * are cheaper to compute. They fulfill their purpose here quite well.
          * See:
-         * http://math.stackexchange.com/questions/1954845/bezier-curvature-extrema
+         * https://math.stackexchange.com/questions/1954845/bezier-curvature-extrema
          *
          * @param {Number[]} v the curve values array
          * @return {Number[]} the roots of all found peaks
diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js
index b9369ed3..ba8dc94a 100644
--- a/src/path/PathItem.Boolean.js
+++ b/src/path/PathItem.Boolean.js
@@ -25,7 +25,7 @@
  * @author Harikrishnan Gopalakrishnan <hari.exeption@gmail.com>
  * @author Jan Boesenberg <development@iconexperience.com>
  * @author Juerg Lehni <juerg@scratchdisk.com>
- * http://hkrish.com/playground/paperjs/booleanStudy.html
+ * https://hkrish.com/playground/paperjs/booleanStudy.html
  */
 PathItem.inject(new function() {
     var min = Math.min,
diff --git a/src/view/CanvasView.js b/src/view/CanvasView.js
index 3afdfa68..5bc805e3 100644
--- a/src/view/CanvasView.js
+++ b/src/view/CanvasView.js
@@ -49,7 +49,7 @@ var CanvasView = View.extend(/** @lends CanvasView# */{
         this._pixelRatio = 1;
         if (!/^off|false$/.test(PaperScope.getAttribute(canvas, 'hidpi'))) {
             // Hi-DPI Canvas support based on:
-            // http://www.html5rocks.com/en/tutorials/canvas/hidpi/
+            // https://www.html5rocks.com/en/tutorials/canvas/hidpi/
             var deviceRatio = window.devicePixelRatio || 1,
                 backingStoreRatio = DomElement.getPrefixed(ctx,
                         'backingStorePixelRatio') || 1;