diff --git a/core/includes/common.inc b/core/includes/common.inc
index 5e8e2d1..550ed75 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1963,7 +1963,7 @@ function l($text, $path, array $options = array()) {
 
   // Add the "active" class if appropriate.
   if ($variables['url_is_active']) {
-    $variables['options']['attributes']['class'][] = 'active';
+    $variables['options']['attributes']['class'][] = 'is-active';
   }
 
   // Remove all HTML and PHP tags from a tooltip, calling expensive strip_tags()