diff --git a/README.md b/README.md
index 9aa1ac1..b93fc8a 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ object({
     resource_group_name = string
     node_subnet_id      = string
     pod_cidr            = string
-    service_cidr        = string
+    service_cidr        = optional(string)
   })
 ```
 
diff --git a/variables.tf b/variables.tf
index a274599..0256abd 100644
--- a/variables.tf
+++ b/variables.tf
@@ -20,7 +20,7 @@ variable "network" {
     resource_group_name = string
     node_subnet_id      = string
     pod_cidr            = string
-    service_cidr        = string
+    service_cidr        = optional(string)
   })
   description = "Values for the networking configuration of the AKS cluster"
 }