diff --git a/core/modules/system/config/schema/system.schema.yml b/core/modules/system/config/schema/system.schema.yml
index 2c12de19a884e5879bd20cba3a42aafdbb3ecc3a..7d3cf404b56dba62acea8df7e6a2fe21b3b819e1 100644
--- a/core/modules/system/config/schema/system.schema.yml
+++ b/core/modules/system/config/schema/system.schema.yml
@@ -180,6 +180,10 @@ system.performance:
         gzip:
           type: boolean
           label: 'Compress JavaScript files.'
+    stale_file_threshold:
+      type: integer
+      label: 'Stale file threshold'
+      deprecated: 'The system.performance.stale_file_threshold config key is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. See https://www.drupal.org/node/3301744'
 
 system.rss:
   type: config_object