diff --git a/solutions/fully-configurable/variables.tf b/solutions/fully-configurable/variables.tf
index 68f9e80b..0e81733e 100644
--- a/solutions/fully-configurable/variables.tf
+++ b/solutions/fully-configurable/variables.tf
@@ -414,7 +414,7 @@ variable "kms_endpoint_type" {
   default     = "private"
   nullable    = false
   validation {
-    condition     = can(regex("public|private", var.kms_endpoint_type))
+    condition     = can(regex("^(public|private)$", var.kms_endpoint_type))
     error_message = "The kms_endpoint_type value must be 'public' or 'private'."
   }
 }