diff --git a/core/modules/config_translation/templates/config_translation_manage_form_element.html.twig b/core/modules/config_translation/templates/config_translation_manage_form_element.html.twig
index 672f5677f60ddab7026b2b5d969231474cf42d98..777514f41bfd753af37d2c5791081bcd39409116 100644
--- a/core/modules/config_translation/templates/config_translation_manage_form_element.html.twig
+++ b/core/modules/config_translation/templates/config_translation_manage_form_element.html.twig
@@ -15,10 +15,10 @@
  */
 #}
 <div class="translation-set clearfix">
-  <div class="layout-column half translation-set__source">
+  <div class="layout-column layout-column--half translation-set__source">
     {{ element.source }}
   </div>
-  <div class="layout-column half translation-set__translated">
+  <div class="layout-column layout-column--half translation-set__translated">
     {{ element.translation }}
   </div>
 </div>
diff --git a/core/modules/help/src/Controller/HelpController.php b/core/modules/help/src/Controller/HelpController.php
index 4ebd4c8ef3b857018d4611468af3c003b690a168..dcb50bdf0a27b99a4023f818773ce44a28b09522 100644
--- a/core/modules/help/src/Controller/HelpController.php
+++ b/core/modules/help/src/Controller/HelpController.php
@@ -77,7 +77,7 @@ protected function helpLinksAsList() {
     $column = array(
       '#type' => 'container',
       'links' => array('#theme' => 'item_list'),
-      '#attributes' => array('class' => array('layout-column', 'quarter')),
+      '#attributes' => array('class' => array('layout-column', 'layout-column--quarter')),
     );
     $output = array(
       '#prefix' => '<div class="clearfix">',
diff --git a/core/modules/system/css/system.admin.css b/core/modules/system/css/system.admin.css
index b01e405211174ae0588910e96a83357fa0f4753b..1d9a51c981cfdded84a00b006396a40b46e8fb49 100644
--- a/core/modules/system/css/system.admin.css
+++ b/core/modules/system/css/system.admin.css
@@ -33,13 +33,13 @@
     padding-right: 10px;
     padding-left: 0;
   }
-  .layout-column.half {
+  .layout-column--half {
     width: 50%;
   }
-  .layout-column.quarter {
+  .layout-column--quarter {
     width: 25%;
   }
-  .layout-column.three-quarter {
+  .layout-column--three-quarter {
     width: 75%;
   }
 }
diff --git a/core/modules/system/templates/admin-page.html.twig b/core/modules/system/templates/admin-page.html.twig
index 038b1af2a6eb45ef8c6fb5c39cebc02a8856e229..b3808e468d769fe107576f483a549d7f02548420 100644
--- a/core/modules/system/templates/admin-page.html.twig
+++ b/core/modules/system/templates/admin-page.html.twig
@@ -17,7 +17,7 @@
 <div class="clearfix">
   {{ system_compact_link }}
   {% for container in containers %}
-    <div class="layout-column half">
+    <div class="layout-column--half">
       {% for block in container.blocks %}
         {{ block }}
       {% endfor %}
diff --git a/core/modules/update/templates/update-version.html.twig b/core/modules/update/templates/update-version.html.twig
index 612f5d4f9b6d1617c1dd045157651de5d1f77031..2d5520fa58d26c3d8c439c5699637e63819578f1 100644
--- a/core/modules/update/templates/update-version.html.twig
+++ b/core/modules/update/templates/update-version.html.twig
@@ -19,12 +19,12 @@
 #}
 <div class="{{ attributes.class }} project-update__version"{{ attributes|without('class') }}>
   <div class="clearfix">
-    <div class="project-update__version-title layout-column quarter">{{ title }}</div>
-    <div class="project-update__version-details layout-column quarter">
+    <div class="project-update__version-title layout-column layout-column--quarter">{{ title }}</div>
+    <div class="project-update__version-details layout-column layout-column--quarter">
       <a href="{{ version.release_link }}">{{ version.version }}</a>
       <span class="project-update__version-date">({{ version.date|date('Y-M-d') }})</span>
     </div>
-    <div class="layout-column half">
+    <div class="layout-column layout-column--half">
       <ul class="project-update__version-links">
         <li class="project-update__download-link">
           <a href="{{ version.download_link }}">{{ 'Download'|t }}</a>