diff --git a/variables.tf b/variables.tf
index c1dfafde89cd291195cb2e9d88fade9789cd662f..b70c805baf5b7b6d31af9be65d40a50f8cb15cbb 100644
--- a/variables.tf
+++ b/variables.tf
@@ -1,7 +1,19 @@
-variable "notes" {}
-variable "mode" {}
-variable "configuration_target" {}
-variable "configuration_value" {}
+variable "notes" {
+  default = ""
+}
+
+variable "mode" {
+  default = ""
+}
+
+variable "configuration_target" {
+  default = ""
+}
+
+variable "configuration_value" {
+  default = ""
+}
+
 variable "zone" {}
 
 variable "whitelist_ips" {