diff --git a/inc/display.php b/inc/display.php
index afbe537..ae5b81c 100644
--- a/inc/display.php
+++ b/inc/display.php
@@ -33,6 +33,8 @@ class Display {
                 add_action('display_alerts', array(__CLASS__, 'display_alerts'));
                 break;
         }
+
+        add_filter('body_class', [__CLASS__, 'body_class'], 10, 1);
     }
 
     static function enqueue_scripts() {
@@ -56,6 +58,17 @@ class Display {
         self::load_template('loop-end');
     }
 
+    static function body_class($classes) {
+        if (is_admin() || !\OgreAlert\Alert::has_active()) return $classes;
+
+        $classes[] = 'has-alert';
+        foreach (\OgreAlert\Alert::get_active() as $id) {
+            $classes[] = sprintf('has-alert-%d', $id);
+        }
+
+        return $classes;
+    }
+
     private static function load_template($filename, $filepart = '', $echo = true, $vars = array()) {
         $path = \OgreAlert\Settings::get('path') . 'templates/' . $filename . '-' . $filepart . '.php';
         if (!file_exists($path)) {