diff --git a/variables.tf b/variables.tf
index 37c0c9ed..9f431243 100644
--- a/variables.tf
+++ b/variables.tf
@@ -55,8 +55,8 @@ variable "distribution" {
   type        = string
   description = "(Required) What is the OS distribution of the instance on which Terraoform Enterprise will be deployed?"
   validation {
-    condition     = contains(["rhel", "ubuntu"], var.distribution)
-    error_message = "Supported values for distribution are 'rhel' or 'ubuntu'."
+    condition     = contains(["rhel", "ubuntu", "amazon-linux-2023"], var.distribution)
+    error_message = "Supported values for distribution are 'rhel', 'ubuntu' or 'amazon-linux-2023'."
   }
 }