diff --git a/.terraform.lock.hcl b/.terraform.lock.hcl
index 6423eee..03308bf 100644
--- a/.terraform.lock.hcl
+++ b/.terraform.lock.hcl
@@ -5,6 +5,7 @@ provider "registry.terraform.io/hetznercloud/hcloud" {
   version     = "1.35.2"
   constraints = "~> 1.0"
   hashes = [
+    "h1:Ryo51oTgIa68cQjD1Ni3sSwTatzS47noAGzDZxt3Yxg=",
     "h1:a/DH+2jHvgikSDajup5feRZRUwNw8OT9NBPKezjgM5g=",
     "zh:1a7cb8f9cbd51b62bdbb4f36cdb070dd99059d86115c4777193e0f8536798d4d",
     "zh:29c104aae7f7a4e1a4aea32febc9caa2d7d86589cd9d01d5b93dbe2cb0a73220",
diff --git a/README.md b/README.md
index 5a7b4f4..7dae666 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,7 @@ module "hcloud_firewall" {
 
 | Name | Version |
 |------|---------|
-| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.0 |
+| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.3 |
 | <a name="requirement_hcloud"></a> [hcloud](#requirement\_hcloud) | ~> 1.0 |
 
 ## Providers
diff --git a/versions.tf b/versions.tf
index 093e8cc..8bc6ab8 100644
--- a/versions.tf
+++ b/versions.tf
@@ -6,6 +6,5 @@ terraform {
     }
   }
 
-  experiments      = [module_variable_optional_attrs]
-  required_version = ">= 1.0"
+  required_version = ">= 1.3"
 }