diff -u b/core/modules/system/config/system.file.yml b/core/modules/system/config/system.file.yml
--- b/core/modules/system/config/system.file.yml
+++ b/core/modules/system/config/system.file.yml
@@ -7,2 +7,2 @@
-  directory: 0775
-  file: 0664
+  directory: '0775'
+  file: '0664'