diff --git a/_InstallPackages/picturefill_2.3.0.zip b/_InstallPackages/picturefill_2.3.0.zip
deleted file mode 100644
index b44270a1..00000000
Binary files a/_InstallPackages/picturefill_2.3.0.zip and /dev/null differ
diff --git a/_InstallPackages/picturefill_2.3.1.zip b/_InstallPackages/picturefill_2.3.1.zip
new file mode 100644
index 00000000..93a62939
Binary files /dev/null and b/_InstallPackages/picturefill_2.3.1.zip differ
diff --git a/picturefill_2.3.0/CHANGES.htm b/picturefill_2.3.1/CHANGES.htm
similarity index 93%
rename from picturefill_2.3.0/CHANGES.htm
rename to picturefill_2.3.1/CHANGES.htm
index 79b8921a..4fc61656 100644
--- a/picturefill_2.3.0/CHANGES.htm
+++ b/picturefill_2.3.1/CHANGES.htm
@@ -1,4 +1,8 @@
 <ol style="max-height: 20em; overflow: auto;">
+  <li>
+    <strong>2.3.1</strong>
+    <p>This release fixes a critical issue with Picturefill's <code>currentSrc</code> support test. This issue caused errors in both the Spartan and WebKit nightlies.</p>
+  </li>
   <li>
     <strong>2.3.0</strong>
     <p>Changes from <a href="#release-2.3.0-beta">Picturefill 2.3 Beta</a></p>
diff --git a/picturefill_2.3.0/LICENSE.htm b/picturefill_2.3.1/LICENSE.htm
similarity index 52%
rename from picturefill_2.3.0/LICENSE.htm
rename to picturefill_2.3.1/LICENSE.htm
index 875f3668..cce7aa9d 100644
--- a/picturefill_2.3.0/LICENSE.htm
+++ b/picturefill_2.3.1/LICENSE.htm
@@ -1 +1 @@
-<p>picturefill is licened under the <a href="https://raw.githubusercontent.com/scottjehl/picturefill/2.3.0/LICENSE">MIT License</a>.</p>
+<p>picturefill is licened under the <a href="https://raw.githubusercontent.com/scottjehl/picturefill/2.3.1/LICENSE">MIT License</a>.</p>
diff --git a/picturefill_2.3.0/picturefill.dnn b/picturefill_2.3.1/picturefill.dnn
similarity index 93%
rename from picturefill_2.3.0/picturefill.dnn
rename to picturefill_2.3.1/picturefill.dnn
index 9e183125..a64bad4a 100644
--- a/picturefill_2.3.0/picturefill.dnn
+++ b/picturefill_2.3.1/picturefill.dnn
@@ -1,6 +1,6 @@
 <dotnetnuke type="Package" version="5.0">
   <packages>
-    <package name="picturefill" type="JavaScript_Library" version="2.3.0">
+    <package name="picturefill" type="JavaScript_Library" version="2.3.1">
       <friendlyName>Picturefill</friendlyName>
       <description><![CDATA[A responsive image polyfill for <code>&lt;picture></code>, <code>srcset</code>, <code>sizes</code>, and more
 <a href="http://scottjehl.github.com/picturefill/">http://scottjehl.github.com/picturefill/</a>]]></description>
@@ -24,7 +24,7 @@
             <libraryName>picturefill</libraryName>
             <fileName>picturefill.js</fileName>
             <preferredScriptLocation>BodyBottom</preferredScriptLocation>
-            <CDNPath>https://cdn.jsdelivr.net/picturefill/2.3.0/picturefill.min.js</CDNPath>
+            <CDNPath>https://cdn.jsdelivr.net/picturefill/2.3.1/picturefill.min.js</CDNPath>
             <objectName>picturefill</objectName>
           </javaScriptLibrary>
         </component>
diff --git a/picturefill_2.3.0/picturefill.js b/picturefill_2.3.1/picturefill.js
similarity index 98%
rename from picturefill_2.3.0/picturefill.js
rename to picturefill_2.3.1/picturefill.js
index 29c20245..d1d86c8b 100644
--- a/picturefill_2.3.0/picturefill.js
+++ b/picturefill_2.3.1/picturefill.js
@@ -1,4 +1,4 @@
-/*! Picturefill - v2.3.0 - 2015-03-23
+/*! Picturefill - v2.3.1 - 2015-04-09
 * http://scottjehl.github.io/picturefill
 * Copyright (c) 2015 https://github.com/scottjehl/picturefill/blob/master/Authors.txt; Licensed MIT */
 /*! matchMedia() polyfill - Test a CSS media type/query in JS. Authors & copyright (c) 2012: Scott Jehl, Paul Irish, Nicholas Zakas, David Knight. Dual MIT/BSD license */
@@ -92,6 +92,7 @@ window.matchMedia || (window.matchMedia = function() {
 	(function() {
 		pf.srcsetSupported = "srcset" in image;
 		pf.sizesSupported = "sizes" in image;
+		pf.curSrcSupported = "currentSrc" in image;
 	})();
 
 	// just a string trim workaround
@@ -504,7 +505,9 @@ window.matchMedia || (window.matchMedia = function() {
 					picImg.src = bestCandidate.url;
 					// currentSrc attribute and property to match
 					// http://picture.responsiveimages.org/#the-img-element
-					picImg.currentSrc = picImg.src;
+					if ( !pf.curSrcSupported ) {
+						picImg.currentSrc = picImg.src;
+					}
 
 					pf.backfaceVisibilityFix( picImg );
 				}
@@ -707,17 +710,13 @@ window.matchMedia || (window.matchMedia = function() {
 			}
 		}, 250 );
 
+		var resizeTimer;
+		var handleResize = function() {
+	        picturefill({ reevaluate: true });
+	    };
 		function checkResize() {
-			var resizeThrottle;
-
-			if ( !w._picturefillWorking ) {
-				w._picturefillWorking = true;
-				w.clearTimeout( resizeThrottle );
-				resizeThrottle = w.setTimeout( function() {
-					picturefill({ reevaluate: true });
-					w._picturefillWorking = false;
-				}, 60 );
-			}
+		    clearTimeout(resizeTimer);
+		    resizeTimer = setTimeout( handleResize, 60 );
 		}
 
 		if ( w.addEventListener ) {