diff --git a/schemas/2020-12-01/Microsoft.Cache.json b/schemas/2020-12-01/Microsoft.Cache.json
index cfe0d30dd8..1457acaad1 100644
--- a/schemas/2020-12-01/Microsoft.Cache.json
+++ b/schemas/2020-12-01/Microsoft.Cache.json
@@ -817,8 +817,9 @@
         },
         "maintenanceWindow": {
           "type": "string",
+          "default": "PT5H",
           "format": "duration",
-          "description": "ISO8601 timespan specifying how much time cache patching can take. "
+          "description": "ISO8601 timespan specifying how much time cache patching can take."
         },
         "startHourUtc": {
           "oneOf": [