diff --git a/README.md b/README.md
index 2ca5be0..b6b732a 100644
--- a/README.md
+++ b/README.md
@@ -110,6 +110,7 @@ module "fck-nat" {
 | <a name="output_launch_template_id"></a> [launch\_template\_id](#output\_launch\_template\_id) | The ID of the launch template used to spawn fck-nat instances |
 | <a name="output_name"></a> [name](#output\_name) | Name used for resources created within the module |
 | <a name="output_role_arn"></a> [role\_arn](#output\_role\_arn) | The ARN of the role used by the fck-nat instance profile |
-| <a name="output_security_group_id"></a> [security\_group\_id](#output\_security\_group\_id) | The ID of the security group used by fck-nat ENIs |
+| <a name="output_security_group_id"></a> [security\_group\_id](#output\_security\_group\_id) | Deprecated. The ID of the security group used by fck-nat ENIs |
+| <a name="output_security_group_ids"></a> [security\_group\_ids](#output\_security\_group\_ids) | List of security group IDs used by fck-nat ENIs |
 | <a name="output_subnet_id"></a> [subnet\_id](#output\_subnet\_id) | Subnet ID to which the fck-nat instance is deployed into |
 | <a name="output_vpc_id"></a> [vpc\_id](#output\_vpc\_id) | VPC ID to which the fck-nat instance is deployed into |
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