diff --git a/wp-includes/class.wp-styles.php b/wp-includes/class.wp-styles.php
index 463b9a3645..fa3f958b85 100644
--- a/wp-includes/class.wp-styles.php
+++ b/wp-includes/class.wp-styles.php
@@ -86,6 +86,10 @@ class WP_Styles extends WP_Dependencies {
 		}
 
 		$href = $this->_css_href( $obj->src, $ver, $handle );
+		if ( ! $href ) {
+			return true;
+		}
+
 		$rel = isset($obj->extra['alt']) && $obj->extra['alt'] ? 'alternate stylesheet' : 'stylesheet';
 		$title = isset($obj->extra['title']) ? "title='" . esc_attr( $obj->extra['title'] ) . "'" : '';
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e182d71481..3b6e7cd81f 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5-alpha-36589';
+$wp_version = '4.5-alpha-36590';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.