diff --git a/README.md b/README.md
index b4122903..e829600f 100644
--- a/README.md
+++ b/README.md
@@ -332,7 +332,7 @@ No modules.
 | <a name="input_log_analytics_workspace_resource_group_name"></a> [log\_analytics\_workspace\_resource\_group\_name](#input\_log\_analytics\_workspace\_resource\_group\_name) | (Optional) Resource group name to create azurerm\_log\_analytics\_solution. | `string` | `null` | no |
 | <a name="input_log_analytics_workspace_sku"></a> [log\_analytics\_workspace\_sku](#input\_log\_analytics\_workspace\_sku) | The SKU (pricing level) of the Log Analytics workspace. For new subscriptions the SKU should be set to PerGB2018 | `string` | `"PerGB2018"` | no |
 | <a name="input_log_retention_in_days"></a> [log\_retention\_in\_days](#input\_log\_retention\_in\_days) | The retention period for the logs in days | `number` | `30` | no |
-| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | (Optional) Maintenance configuration of the managed cluster. | <pre>object({<br>    allowed = list(object({<br>      day   = string<br>      hours = set(number)<br>    })),<br>    not_allowed = list(object({<br>      end   = string<br>      start = string<br>    })),<br>  })</pre> | `null` | no |
+| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | (Optional) Maintenance configuration of the managed cluster. | <pre>object({<br>    allowed = optional(list(object({<br>      day   = string<br>      hours = set(number)<br>    })), []),<br>    not_allowed = optional(list(object({<br>      end   = string<br>      start = string<br>    })), []),<br>  })</pre> | `null` | no |
 | <a name="input_maintenance_window_node_os"></a> [maintenance\_window\_node\_os](#input\_maintenance\_window\_node\_os) | - `day_of_month` -<br>- `day_of_week` - (Optional) The day of the week for the maintenance run. Options are `Monday`, `Tuesday`, `Wednesday`, `Thurday`, `Friday`, `Saturday` and `Sunday`. Required in combination with weekly frequency.<br>- `duration` - (Required) The duration of the window for maintenance to run in hours.<br>- `frequency` - (Required) Frequency of maintenance. Possible options are `Daily`, `Weekly`, `AbsoluteMonthly` and `RelativeMonthly`.<br>- `interval` - (Required) The interval for maintenance runs. Depending on the frequency this interval is week or month based.<br>- `start_date` - (Optional) The date on which the maintenance window begins to take effect.<br>- `start_time` - (Optional) The time for maintenance to begin, based on the timezone determined by `utc_offset`. Format is `HH:mm`.<br>- `utc_offset` - (Optional) Used to determine the timezone for cluster maintenance.<br>- `week_index` - (Optional) The week in the month used for the maintenance run. Options are `First`, `Second`, `Third`, `Fourth`, and `Last`.<br><br>---<br>`not_allowed` block supports the following:<br>- `end` - (Required) The end of a time span, formatted as an RFC3339 string.<br>- `start` - (Required) The start of a time span, formatted as an RFC3339 string. | <pre>object({<br>    day_of_month = optional(number)<br>    day_of_week  = optional(string)<br>    duration     = number<br>    frequency    = string<br>    interval     = number<br>    start_date   = optional(string)<br>    start_time   = optional(string)<br>    utc_offset   = optional(string)<br>    week_index   = optional(string)<br>    not_allowed = optional(set(object({<br>      end   = string<br>      start = string<br>    })))<br>  })</pre> | `null` | no |
 | <a name="input_microsoft_defender_enabled"></a> [microsoft\_defender\_enabled](#input\_microsoft\_defender\_enabled) | (Optional) Is Microsoft Defender on the cluster enabled? Requires `var.log_analytics_workspace_enabled` to be `true` to set this variable to `true`. | `bool` | `false` | no |
 | <a name="input_monitor_metrics"></a> [monitor\_metrics](#input\_monitor\_metrics) | (Optional) Specifies a Prometheus add-on profile for the Kubernetes Cluster<br>object({<br>  annotations\_allowed = "(Optional) Specifies a comma-separated list of Kubernetes annotation keys that will be used in the resource's labels metric."<br>  labels\_allowed      = "(Optional) Specifies a Comma-separated list of additional Kubernetes label keys that will be used in the resource's labels metric."<br>}) | <pre>object({<br>    annotations_allowed = optional(string)<br>    labels_allowed      = optional(string)<br>  })</pre> | `null` | no |
diff --git a/variables.tf b/variables.tf
index ea9abbe4..184f0579 100644
--- a/variables.tf
+++ b/variables.tf
@@ -641,14 +641,14 @@ variable "log_retention_in_days" {
 
 variable "maintenance_window" {
   type = object({
-    allowed = list(object({
+    allowed = optional(list(object({
       day   = string
       hours = set(number)
-    })),
-    not_allowed = list(object({
+    })), []),
+    not_allowed = optional(list(object({
       end   = string
       start = string
-    })),
+    })), []),
   })
   default     = null
   description = "(Optional) Maintenance configuration of the managed cluster."