diff --git a/subnets/variables.tf b/subnets/variables.tf
new file mode 100644
index 0000000..38ced37
--- /dev/null
+++ b/subnets/variables.tf
@@ -0,0 +1,5 @@
+variable "vpc_id" {
+  description = "VPC ID"
+  type        = string
+}
+