diff --git a/core/modules/layout_discovery/layouts/onecol/layout--onecol.html.twig b/core/modules/layout_discovery/layouts/onecol/layout--onecol.html.twig
index 6f1bade..2d66b78 100644
--- a/core/modules/layout_discovery/layouts/onecol/layout--onecol.html.twig
+++ b/core/modules/layout_discovery/layouts/onecol/layout--onecol.html.twig
@@ -12,7 +12,7 @@
 #}
 {%
   set classes = [
-    'layout--onecol',
+    'layout layout--onecol',
   ]
 %}
 {% if content %}
diff --git a/core/modules/layout_discovery/layouts/threecol_25_50_25/layout--threecol-25-50-25.html.twig b/core/modules/layout_discovery/layouts/threecol_25_50_25/layout--threecol-25-50-25.html.twig
index 636c622..deb390d 100644
--- a/core/modules/layout_discovery/layouts/threecol_25_50_25/layout--threecol-25-50-25.html.twig
+++ b/core/modules/layout_discovery/layouts/threecol_25_50_25/layout--threecol-25-50-25.html.twig
@@ -15,7 +15,7 @@
 #}
 {%
   set classes = [
-    'layout--threecol-25-50-25',
+    'layout layout--threecol-25-50-25',
   ]
 %}
 {% if content %}
diff --git a/core/modules/layout_discovery/layouts/threecol_33_34_33/layout--threecol-33-34-33.html.twig b/core/modules/layout_discovery/layouts/threecol_33_34_33/layout--threecol-33-34-33.html.twig
index e7556c2..0a798c9 100644
--- a/core/modules/layout_discovery/layouts/threecol_33_34_33/layout--threecol-33-34-33.html.twig
+++ b/core/modules/layout_discovery/layouts/threecol_33_34_33/layout--threecol-33-34-33.html.twig
@@ -15,7 +15,7 @@
 #}
 {%
   set classes = [
-    'layout--threecol-33-34-33',
+    'layout layout--threecol-33-34-33',
   ]
 %}
 {% if content %}
diff --git a/core/modules/layout_discovery/layouts/twocol/layout--twocol.html.twig b/core/modules/layout_discovery/layouts/twocol/layout--twocol.html.twig
index 4d22cb2..8669020 100644
--- a/core/modules/layout_discovery/layouts/twocol/layout--twocol.html.twig
+++ b/core/modules/layout_discovery/layouts/twocol/layout--twocol.html.twig
@@ -12,7 +12,7 @@
 #}
 {%
   set classes = [
-    'layout--twocol',
+    'layout layout--twocol',
   ]
 %}
 {% if content %}
diff --git a/core/modules/layout_discovery/layouts/twocol_bricks/layout--twocol-bricks.html.twig b/core/modules/layout_discovery/layouts/twocol_bricks/layout--twocol-bricks.html.twig
index ad09208..1a99143 100644
--- a/core/modules/layout_discovery/layouts/twocol_bricks/layout--twocol-bricks.html.twig
+++ b/core/modules/layout_discovery/layouts/twocol_bricks/layout--twocol-bricks.html.twig
@@ -15,7 +15,7 @@
 #}
 {%
   set classes = [
-    'layout--twocol-bricks',
+    'layout layout--twocol-bricks',
   ]
 %}
 {% if content %}
diff --git a/core/modules/layout_discovery/templates/layout.html.twig b/core/modules/layout_discovery/templates/layout.html.twig
index 7b8f0bc..6b588dd 100644
--- a/core/modules/layout_discovery/templates/layout.html.twig
+++ b/core/modules/layout_discovery/templates/layout.html.twig
@@ -6,7 +6,7 @@
 #}
 {%
   set classes = [
-    'layout--' ~ layout.id|clean_class,
+    'layout layout--' ~ layout.id|clean_class,
   ]
 %}
 {% if content %}