diff --git a/README.md b/README.md
index 15768b5..209eb06 100644
--- a/README.md
+++ b/README.md
@@ -90,7 +90,7 @@ module "dynamic_subnets" {
   availability_zones = ["us-west-2a","us-west-2b","us-west-2c"]
   vpc_id             = module.vpc.vpc_id
   igw_id             = [module.vpc.igw_id]
-  cidr_block         = "10.0.0.0/16"
+  ipv4_cidr_block    = ["10.0.0.0/16"]
 }
 ```