diff --git a/core/modules/system/config/schema/system.schema.yml b/core/modules/system/config/schema/system.schema.yml
index 5385fd7..04ad598 100644
--- a/core/modules/system/config/schema/system.schema.yml
+++ b/core/modules/system/config/schema/system.schema.yml
@@ -1,44 +1,44 @@
-# Schema for configuration files of system module:
+# Schema for configuration files of system module.
 system.site:
   type: mapping
   label: 'Site information'
   mapping:
-    "name":
-      label: "Site name"
+    name:
+      label: 'Site name'
       type: label
-    "mail":
-      label: "Site mail"
+    mail:
+      label: 'Site mail'
       type: email
-    "slogan":
-      label: "Site slogan"
+    slogan:
+      label: 'Site slogan'
       type: text
-    "page":
+    page:
       type: mapping
-      label: "Pages"
+      label: 'Pages'
       mapping:
-        "403":
+        403:
           type: path
-          label: "Default 403 (access denied) page"
-        "404":
+          label: 'Default 403 (access denied) page'
+        404:
           type: path
-          label: "Default 404 (not found) page"
-        "front":
+          label: 'Default 404 (not found) page'
+        front:
           type: path
-          label: "Front page path"
-    "admin_compact_mode":
+          label: 'Front page path'
+    admin_compact_mode:
       type: boolean
-      label: "Admin compact mode"
-    "weight_select_max":
+      label: 'Admin compact mode'
+    weight_select_max:
       type: integer
-      label: "Weight field maximum value"
+      label: 'Weight field maximum value'
 
 system.maintenance:
   type: mapping
   label: 'Maintenance mode'
   mapping:
-    "enabled":
+    enabled:
       type: boolean
-      label: "Put site into maintenance mode"
-    "message":
+      label: 'Put site into maintenance mode'
+    message:
       type: text
-      label: "Message to display when in maintenance mode"
+      label: 'Message to display when in maintenance mode'