diff --git a/Imager.js b/Imager.js
index 19d3c1b..d3b4022 100644
--- a/Imager.js
+++ b/Imager.js
@@ -124,6 +124,8 @@
         this.widthsMap        = {};
         this.refreshPixelRatio();
         this.widthInterpolator = opts.widthInterpolator || returnFn;
+        this.widthInterpolationSelector = !opts.widthInterpolationSelector ? new RegExp('{width}', 'g') : new RegExp(opts.widthInterpolationSelector, 'g');
+        this.pixelRatioInterpolationSelector = !opts.pixelRatioInterpolationSelector ? new RegExp('{pixel_ratio}', 'g') : new RegExp(opts.pixelRatioInterpolationSelector, 'g');
 
         // Needed as IE8 adds a default `width`/`height` attribute…
         this.gif.removeAttribute('height');
@@ -360,8 +362,8 @@
 
     Imager.prototype.changeImageSrcToUseNewImageDimensions = function (src, selectedWidth) {
         return src
-            .replace(/{width}/g, Imager.transforms.width(selectedWidth, this.widthsMap))
-            .replace(/{pixel_ratio}/g, Imager.transforms.pixelRatio(this.devicePixelRatio));
+            .replace(this.widthInterpolationSelector, Imager.transforms.width(selectedWidth, this.widthsMap))
+            .replace(this.pixelRatioInterpolationSelector, Imager.transforms.pixelRatio(this.devicePixelRatio));
     };
 
     Imager.getPixelRatio = function getPixelRatio(context) {
diff --git a/test/fixtures/custom-matcher.html b/test/fixtures/custom-matcher.html
new file mode 100644
index 0000000..e383a73
--- /dev/null
+++ b/test/fixtures/custom-matcher.html
@@ -0,0 +1,3 @@
+<div class="delayed-image-load" data-src="base/test/fixtures/media/C-xxwidthxx.jpg"></div>
+<div class="delayed-image-load" data-src="base/test/fixtures/media/B-xxwidthxx.jpg" data-width="640"></div>
+<div class="delayed-image-load" data-src="base/test/fixtures/media-xxwidthxx/fillmurray.jpg" data-width="320"></div>
diff --git a/test/unit/html-options.js b/test/unit/html-options.js
index d81975a..1e3b42c 100644
--- a/test/unit/html-options.js
+++ b/test/unit/html-options.js
@@ -17,6 +17,22 @@ describe('Imager.js HTML data-* API', function () {
         cleanFixtures(fixtures);
     });
 
+    describe('customising matcher for interpolation', function () {
+      it('should successfully resolve custom match expression', function (done) {
+        fixtures = loadFixtures('custom-matcher');
+        var imgr = new Imager({availableWidths: [320, 640], widthInterpolationSelector: 'xxwidthxx'});
+
+        imgr.ready(function () {
+          var src = applyEach(imgr.divs, function (el) {
+            return el.getAttribute('src');
+          });
+
+          expect(src).to.eql(['base/test/fixtures/media/C-640.jpg', 'base/test/fixtures/media/B-640.jpg', 'base/test/fixtures/media-320/fillmurray.jpg']);
+          done();
+        });
+      });
+    });
+
     describe('handling {width} in data-src', function () {
         it('should not use RegExp anymore', function (done) {
             fixtures = loadFixtures('data-src-old');