diff --git a/README.md b/README.md
index 5c0ab71..709ddad 100644
--- a/README.md
+++ b/README.md
@@ -61,15 +61,15 @@ No modules.
 
 ## Inputs
 
-| Name                                                                                                                                    | Description                                                                                                               | Type           | Default | Required |
-| --------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | -------------- | ------- | :------: |
-| <a name="input_project"></a> [project](#input\_project) | Project name | `string` | n/a | yes |
-| <a name="input_env"></a> [env](#input\_env) | Environment name | `string` | n/a | yes |
-| <a name="input_location"></a> [location](#input\_location) | Specifies the supported Azure location where the resource exists | `string` | n/a | yes |
-| <a name="input_resource_group"></a> [resource\_group](#input\_resource\_group) | The name of the resource group in which resources is created | `string` | n/a | yes |
-| <a name="input_tags"></a> [tags](#input\_tags) | A mapping of tags to assign to the resource | `map(string)` | {} | no |
-| <a name="input_custom_nsg_name"></a> [custom\_nsg\_name](#input\_custom\_nsg\_name) | Custom network security group name | `string` | null | no |
-| <a name="input_security_rules"></a> [security\_rules](#input\_security\_rules) | List of objects representing security rules | <pre>list(object({<br> name                       = optional(string)<br> description                = optional(string)<br> priority                   = optional(number)<br> direction                  = optional(string)<br> access                     = optional(string)<br> protocol                   = optional(string)<br> source_port_range          = optional(string)<br> destination_port_range     = optional(string)<br> source_address_prefix      = optional(string)<br> destination_address_prefix = optional(string)<br>}))<br></pre> | [] | no |
+| Name                                                                                                                                    | Description                                                                                                               | Type                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Default | Required |
+| --------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| ------- | :------: |
+| <a name="input_project"></a> [project](#input\_project) | Project name | `string`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | n/a | yes |
+| <a name="input_env"></a> [env](#input\_env) | Environment name | `string`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | n/a | yes |
+| <a name="input_location"></a> [location](#input\_location) | Specifies the supported Azure location where the resource exists | `string`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | n/a | yes |
+| <a name="input_resource_group"></a> [resource\_group](#input\_resource\_group) | The name of the resource group in which resources is created | `string`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | n/a | yes |
+| <a name="input_tags"></a> [tags](#input\_tags) | A mapping of tags to assign to the resource | `map(string)`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | {} | no |
+| <a name="input_custom_nsg_name"></a> [custom\_nsg\_name](#input\_custom\_nsg\_name) | Custom network security group name | `string`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | null | no |
+| <a name="input_security_rules"></a> [security\_rules](#input\_security\_rules) | List of objects representing security rules | <pre>list(object({<br> name                       = optional(string)<br> description                = optional(string)<br> priority                   = optional(number)<br> direction                  = optional(string)<br> access                     = optional(string)<br> protocol                   = optional(string)<br> source_port_range          = optional(string)<br> destination_port_range     = optional(string)<br> source_address_prefix      = optional(string)<br> source_address_prefixes    = optional(list(string))<br> destination_address_prefix = optional(string)<br>}))<br></pre> | [] | no |
 
 
 ## Outputs
diff --git a/main.tf b/main.tf
index 45c3251..08fa69e 100644
--- a/main.tf
+++ b/main.tf
@@ -20,7 +20,8 @@ resource "azurerm_network_security_group" "this" {
       protocol                   = security_rule.value["protocol"]
       source_port_range          = security_rule.value["source_port_range"]
       destination_port_range     = security_rule.value["destination_port_range"]
-      source_address_prefix      = security_rule.value["source_address_prefix"]
+      source_address_prefix      = lookup(security_rule.value, "source_address_prefix", null)
+      source_address_prefixes    = lookup(security_rule.value, "source_address_prefixes", [])
       destination_address_prefix = security_rule.value["destination_address_prefix"]
     }
   }
diff --git a/variables.tf b/variables.tf
index 164a9a7..c802e97 100644
--- a/variables.tf
+++ b/variables.tf
@@ -41,6 +41,7 @@ variable "security_rules" {
     source_port_range          = optional(string)
     destination_port_range     = optional(string)
     source_address_prefix      = optional(string)
+    source_address_prefixes    = optional(list(string))
     destination_address_prefix = optional(string)
   }))
   description = "List of objects representing security rules"