diff --git a/flickable.js b/flickable.js
index 5b38d52..35c4031 100644
--- a/flickable.js
+++ b/flickable.js
@@ -17,7 +17,10 @@ var Flickable = function(elementSelector, options) {
             nextButtonClass: 'nextSlideButton',
             prevButtonClass: 'prevSlideButton',
             nextButtonText: 'Next',
-            prevButtonText: 'Previous'
+            prevButtonText: 'Previous',
+            widthCallback: function() {
+                return window.innerWidth;
+            }
         },
         orientationEvent = 'resize',
         orientationTimeout;
@@ -47,11 +50,11 @@ var Flickable = function(elementSelector, options) {
 
     if (settings.width == 'screen') {
         settings.widthScreen = true;
-        settings.width = window.innerWidth;
+        settings.width = settings.widthCallback();
         window.addEventListener(orientationEvent, function(e) {
             clearTimeout(orientationTimeout);
             orientationTimeout = setTimeout(function() {
-                settings.width = window.innerWidth;
+                settings.width = settings.widthCallback();
             }, 200);
         });
     }
diff --git a/readme.md b/readme.md
index c838a98..c241c81 100644
--- a/readme.md
+++ b/readme.md
@@ -48,5 +48,6 @@ Settings reference
 - `indicatorClass`: The class name for the indicator wrapper element. **Default:** `'flickableIndicator'`
 - `activeIndicatorClass`: The class name for the active indicator element. **Default:** `'flickableIndicatorActive'`
 - `callback`: A function to be called each time the slide changes. The function will be passed the slide number (zero-indexed) as a parameter.
+- `widthCallback`: A function to be called each time the orientation changes. The function should return new images width.
 
 _Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php_
\ No newline at end of file