diff --git a/variables.tf b/variables.tf
index 4830134..59b021e 100644
--- a/variables.tf
+++ b/variables.tf
@@ -124,8 +124,8 @@ variable "availability_zone_count" {
   description = "Number of Availability Zones for the domain to use."
 
   validation {
-    condition     = contains([2, 3], var.availability_zone_count)
-    error_message = "The availibility zone count must be 2 or 3."
+    condition     = contains([2, 3], var.availability_zone_count) && var.zone_awareness_enabled == "true"
+    error_message = "The availibility zone count must be 2 or 3 when Zone Awareness is Enabled."
   }
 }