diff --git a/core/modules/system/system.libraries.yml b/core/modules/system/system.libraries.yml
index 9493f52..b9627fc 100644
--- a/core/modules/system/system.libraries.yml
+++ b/core/modules/system/system.libraries.yml
@@ -35,7 +35,6 @@ base:
       css/components/link.theme.css: { weight: -10 }
       css/components/links.theme.css: { weight: -10 }
       css/components/menu.theme.css: { weight: -10 }
-      css/components/messages.theme.css: { weight: -10 }
       css/components/more-link.theme.css: { weight: -10 }
       css/components/pager.theme.css: { weight: -10 }
       css/components/progress.theme.css: { weight: -10 }
diff --git a/core/themes/classy/classy.libraries.yml b/core/themes/classy/classy.libraries.yml
index af0f891..13f341f 100644
--- a/core/themes/classy/classy.libraries.yml
+++ b/core/themes/classy/classy.libraries.yml
@@ -27,3 +27,9 @@ search.results:
   css:
     theme:
       css/search/search.theme.css: {}
+
+messages:
+  version: VERSION
+  css:
+    theme:
+      css/components/messages.css: {}
diff --git a/core/modules/system/css/components/messages.theme.css b/core/themes/classy/css/components/messages.css
similarity index 100%
rename from core/modules/system/css/components/messages.theme.css
rename to core/themes/classy/css/components/messages.css
diff --git a/core/themes/classy/templates/misc/status-messages.html.twig b/core/themes/classy/templates/misc/status-messages.html.twig
index a58ed8f..da56bcc 100644
--- a/core/themes/classy/templates/misc/status-messages.html.twig
+++ b/core/themes/classy/templates/misc/status-messages.html.twig
@@ -23,6 +23,7 @@
  * @see template_preprocess_status_messages()
  */
 #}
+{{ attach_library('classy/messages') }}
 {% block messages %}
 {% for type, messages in message_list %}
   {%