diff --git a/main.tf b/main.tf
index 5ce15b9..1badb5c 100755
--- a/main.tf
+++ b/main.tf
@@ -168,7 +168,7 @@ module "cognito_userpool_sms_label" {
   source  = "cloudposse/label/null"
   version = "0.25.0"
 
-  attributes = "sms"
+  attributes = ["sms"]
   context    = module.cognito_userpool_label.context
 }