diff --git a/terraform.tfvars.example b/terraform.tfvars.example
index 888bb8a..29fc1a3 100644
--- a/terraform.tfvars.example
+++ b/terraform.tfvars.example
@@ -127,7 +127,8 @@ load_balancer_location = "fsn1"
 # If you want to disable the automatic upgrade of k3s, you can set this to false. The default is "true".
 # automatically_upgrade_k3s = false
 
-# Allows you to specify either stable, latest, or testing (defaults to stable), see https://rancher.com/docs/k3s/latest/en/upgrades/basic/
+# Allows you to specify either stable, latest, testing or supported minor versions (defaults to stable)
+# see https://rancher.com/docs/k3s/latest/en/upgrades/basic/ and https://update.k3s.io/v1-release/channels
 # initial_k3s_channel = "latest"
 
 # The cluster name, by default "k3s"
diff --git a/variables.tf b/variables.tf
index e9726a1..6b7fba8 100644
--- a/variables.tf
+++ b/variables.tf
@@ -101,7 +101,7 @@ variable "initial_k3s_channel" {
   description = "Allows you to specify an initial k3s channel"
 
   validation {
-    condition     = contains(["stable", "latest", "testing"], var.initial_k3s_channel)
+    condition     = contains(["stable", "latest", "testing", "v1.16", "v1.17", "v1.18", "v1.19", "v1.20", "v1.21", "v1.22", "v1.23"], var.initial_k3s_channel)
     error_message = "The initial k3s channel must be one of stable, latest or testing."
   }
 }