diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 78bc8d5..136d77d 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1655,9 +1655,9 @@ function theme_status_messages($variables) {
       $output .= '<h2 class="element-invisible">' . $status_heading[$type] . "</h2>\n";
     }
     if (count($messages) > 1) {
-      $output .= " <ul>\n";
+      $output .= " <ul class=\"messages__list\">\n";
       foreach ($messages as $message) {
-        $output .= '  <li>' . $message . "</li>\n";
+        $output .= '  <li class="messages__item">' . $message . "</li>\n";
       }
       $output .= " </ul>\n";
     }
diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index c67d1a1..19bb45f 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -440,13 +440,13 @@ ul.tabs {
 .messages + .messages {
   margin-top: 1.538em;
 }
-.messages ul {
+.messages__list {
   list-style: none;
   padding: 0;
   margin: 0;
 }
-.messages li + li {
-  margin-top: .769em;
+.messages__item + .messages__item {
+  margin-top: 0.769em;
 }
 
 /* @TODO Separate tables and messages styling */