diff --git a/docs.md b/docs.md
index db1ea782..96054d96 100644
--- a/docs.md
+++ b/docs.md
@@ -489,6 +489,7 @@
 | availability_zones | The list of availability zones of the VPC. |
 | internal_rtb_id | The internal route table ID. |
 | external_rtb_id | The external route table ID. |
+| external_nat_ips | A comma-separated list of internal NAT Gateways IPs. |
 
 # web-service
 
diff --git a/vpc/main.tf b/vpc/main.tf
index 48cdf2de..12a88af7 100644
--- a/vpc/main.tf
+++ b/vpc/main.tf
@@ -181,3 +181,8 @@ output "internal_rtb_id" {
 output "external_rtb_id" {
   value = "${aws_route_table.external.id}"
 }
+
+// The list of EIPs associated with the internal subnets.
+output "internal_nat_ips" {
+  value = ["${aws_eip.nat.*.public_ip}"]
+}