diff --git a/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2021-06-01-preview/postgresql.json b/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2021-06-01-preview/postgresql.json
index 3baa3402d17a..7ccbbb6349f7 100644
--- a/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2021-06-01-preview/postgresql.json
+++ b/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2021-06-01-preview/postgresql.json
@@ -1423,6 +1423,7 @@
         },
         "maintenanceWindow": {
           "$ref": "#/definitions/MaintenanceWindow",
+          "default": null,
           "description": "Maintenance window properties of a server.",
           "x-ms-mutability": [
             "update",
@@ -1525,6 +1526,7 @@
         },
         "maintenanceWindow": {
           "$ref": "#/definitions/MaintenanceWindow",
+          "default": null,
           "description": "Maintenance window properties of a server.",
           "x-ms-mutability": [
             "update",
@@ -1631,6 +1633,7 @@
         "backupRetentionDays": {
           "type": "integer",
           "format": "int32",
+          "default": 7,
           "description": "Backup retention days for the server."
         },
         "geoRedundantBackup": {
diff --git a/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/stable/2021-06-01/postgresql.json b/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/stable/2021-06-01/postgresql.json
index bb28f42fb9f2..63abd95aadf0 100644
--- a/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/stable/2021-06-01/postgresql.json
+++ b/specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/stable/2021-06-01/postgresql.json
@@ -1423,6 +1423,7 @@
         },
         "maintenanceWindow": {
           "$ref": "#/definitions/MaintenanceWindow",
+          "default": null,
           "description": "Maintenance window properties of a server.",
           "x-ms-mutability": [
             "update",
@@ -1525,6 +1526,7 @@
         },
         "maintenanceWindow": {
           "$ref": "#/definitions/MaintenanceWindow",
+          "default": null,
           "description": "Maintenance window properties of a server.",
           "x-ms-mutability": [
             "update",
@@ -1631,6 +1633,7 @@
         "backupRetentionDays": {
           "type": "integer",
           "format": "int32",
+          "default": 7,
           "description": "Backup retention days for the server."
         },
         "geoRedundantBackup": {