diff --git a/src/wp-includes/js/jquery/jquery.masonry.js b/src/wp-includes/js/jquery/jquery.masonry.js
index aceb766dfa..c4228bf4f6 100644
--- a/src/wp-includes/js/jquery/jquery.masonry.js
+++ b/src/wp-includes/js/jquery/jquery.masonry.js
@@ -26,7 +26,7 @@
     var isAniOption = this.options.isAnimated;
     if ( isAniOption !== undefined ) {
       this.options.transitionDuration = isAniOption ?
-        Masonry.prototype.options.transitionDuration : 0;
+        this.options.transitionDuration : 0;
     }
 
     if ( isAniOption === undefined || isAniOption ) {
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 842405c3c9..b4790d4d20 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -250,7 +250,7 @@ function wp_default_scripts( &$scripts ) {
 	// It sets jQuery as a dependency, as the theme may have been implicitly loading it this way.
 	$scripts->add( 'imagesloaded', "/wp-includes/js/imagesloaded.min.js", array(), '3.2.0', 1 );
 	$scripts->add( 'masonry', "/wp-includes/js/masonry.min.js", array( 'imagesloaded' ), '3.3.2', 1 );
-	$scripts->add( 'jquery-masonry', "/wp-includes/js/jquery/jquery.masonry$dev_suffix.js", array( 'jquery', 'masonry' ), '3.1.2', 1 );
+	$scripts->add( 'jquery-masonry', "/wp-includes/js/jquery/jquery.masonry$dev_suffix.js", array( 'jquery', 'masonry' ), '3.1.2a', 1 );
 
 	$scripts->add( 'thickbox', "/wp-includes/js/thickbox/thickbox.js", array('jquery'), '3.1-20121105', 1 );
 	did_action( 'init' ) && $scripts->localize( 'thickbox', 'thickboxL10n', array(