diff --git a/modules/storage/aws-backup/README.md b/modules/storage/aws-backup/README.md
index aa2d575..8553e07 100644
--- a/modules/storage/aws-backup/README.md
+++ b/modules/storage/aws-backup/README.md
@@ -37,7 +37,7 @@ No modules.
 | backup\_kms\_key | KMS key arn for AWS Backup | `string` | `null` | no |
 | daily-backup-cron | Daily backup rule cron expression | `string` | n/a | yes |
 | daily-backup-retention | Daily backup retention period | `number` | n/a | yes |
-| enable-monthly-backup | Enable monthly backup plan | `bool` | `false` | no |
+| enable-monthly-backup | Enable monthly backup plan. In most cases, monthly backup is not useful. | `bool` | `false` | no |
 | enable-vss | Enable VSS for Windows Ec2 | `bool` | `false` | no |
 | monthly-backup-cron | Monthly backup rule cron expression | `string` | `null` | no |
 | monthly-backup-retention | Monthly backup retention period | `number` | `null` | no |
diff --git a/modules/storage/aws-backup/variables.tf b/modules/storage/aws-backup/variables.tf
index a72de2a..db6ce9c 100644
--- a/modules/storage/aws-backup/variables.tf
+++ b/modules/storage/aws-backup/variables.tf
@@ -3,17 +3,23 @@ variable "daily-backup-cron" {
   description = "Daily backup rule cron expression"
 }
 
+variable "daily-backup-retention" {
+  type        = number
+  description = "Daily backup retention period"
+}
+
+variable "enable-monthly-backup" {
+  description = "Enable monthly backup plan. In most cases, monthly backup is not useful."
+  type        = bool
+  default     = false
+}
+
 variable "monthly-backup-cron" {
   type        = string
   description = "Monthly backup rule cron expression"
   default     = null
 }
 
-variable "daily-backup-retention" {
-  type        = number
-  description = "Daily backup retention period"
-}
-
 variable "monthly-backup-retention" {
   type        = number
   description = "Monthly backup retention period"
@@ -49,12 +55,6 @@ variable "backup_kms_key" {
   default     = null
 }
 
-variable "enable-monthly-backup" {
-  description = "Enable monthly backup plan"
-  type        = bool
-  default     = false
-}
-
 variable "enable-vss" {
   type        = bool
   description = "Enable VSS for Windows Ec2"