diff --git a/README.md b/README.md
index 7ce304a..4461e56 100644
--- a/README.md
+++ b/README.md
@@ -32,8 +32,8 @@ No modules.
 |------|-------------|------|---------|:--------:|
 | <a name="input_delete_default_rules"></a> [delete_default_rules](#input_delete_default_rules) | Whether or not to delete the default egress rules applied to the security group.<br>Default rules allow egress ipv4 and ipv6 to 0.0.0.0/0. | `bool` | `false` | no |
 | <a name="input_description"></a> [description](#input_description) | Description for the security group. | `string` | `null` | no |
-| <a name="input_egress_rules"></a> [egress_rules](#input_egress_rules) | The list of egress rules to attach to the security group.<br>You can use all regular entries from the openstack_networking_secgroup_rule_v2 resource<br>provided by the openstack provider, except region, which defaults to the region of the provider used,<br>and direction, which defaults to egress.<br>By default, if ethertype is not specified, it will by IPv4. | `map(map(string))` | n/a | yes |
-| <a name="input_ingress_rules"></a> [ingress_rules](#input_ingress_rules) | The list of ingress rules to attach to the security group.<br>You can use all regular entries from the openstack_networking_secgroup_rule_v2 resource<br>provided by the openstack provider, except region, which defaults to the region of the provider used,<br>and direction, which defaults to ingress.<br>By default, if ethertype is not specified, it will by IPv4. | `map(map(string))` | n/a | yes |
+| <a name="input_egress_rules"></a> [egress_rules](#input_egress_rules) | The list of egress rules to attach to the security group.<br>You can use all regular entries from the openstack_networking_secgroup_rule_v2 resource<br>provided by the openstack provider, except region, which defaults to the region of the provider used,<br>and direction, which defaults to egress.<br>By default, if ethertype is not specified, it will by IPv4. | `map(map(string))` | `{}` | no |
+| <a name="input_ingress_rules"></a> [ingress_rules](#input_ingress_rules) | The list of ingress rules to attach to the security group.<br>You can use all regular entries from the openstack_networking_secgroup_rule_v2 resource<br>provided by the openstack provider, except region, which defaults to the region of the provider used,<br>and direction, which defaults to ingress.<br>By default, if ethertype is not specified, it will by IPv4. | `map(map(string))` | `{}` | no |
 | <a name="input_name"></a> [name](#input_name) | The name of the security group. | `string` | n/a | yes |
 | <a name="input_tags"></a> [tags](#input_tags) | A list of tags (strings) to apply to the security group | `list(string)` | `[]` | no |
 | <a name="input_tenant_id"></a> [tenant_id](#input_tenant_id) | The tenant for which to create the security group.<br>This is only required for admins creating security groups for other tenant. | `string` | `null` | no |
diff --git a/variables.tf b/variables.tf
index cdcd6b9..22f087f 100644
--- a/variables.tf
+++ b/variables.tf
@@ -36,6 +36,7 @@ variable "ingress_rules" {
     and direction, which defaults to ingress.
     By default, if ethertype is not specified, it will by IPv4.
   EOT
+  default     = {}
 }
 
 variable "egress_rules" {
@@ -47,6 +48,7 @@ variable "egress_rules" {
     and direction, which defaults to egress.
     By default, if ethertype is not specified, it will by IPv4.
   EOT
+  default     = {}
 }
 
 variable "tags" {