diff --git a/main.tf b/main.tf
index 48a4e77..e25a043 100644
--- a/main.tf
+++ b/main.tf
@@ -120,7 +120,7 @@ resource "aws_route_table" "quortex_private" {
 
   # Route to the NAT, if NAT is enabled...
   dynamic "route" {
-    for_each = length([for k, v in var.nat_gateways : v if v.subnet_key == each.key]) > 0 ? [1] : []
+    for_each = length([for k, v in aws_nat_gateway.quortex : v.id if v.tags["AvailabilityZone"] == each.value.availability_zone]) > 0 ? [1] : []
 
     content {
       cidr_block     = "0.0.0.0/0"
@@ -130,7 +130,7 @@ resource "aws_route_table" "quortex_private" {
 
   # ...otherwise, route to the Internet Gateway
   dynamic "route" {
-    for_each = length([for k, v in var.nat_gateways : v if v.subnet_key == each.key]) == 0 ? [1] : []
+    for_each = length([for k, v in aws_nat_gateway.quortex : v.id if v.tags["AvailabilityZone"] == each.value.availability_zone]) == 0 ? [1] : []
 
     content {
       cidr_block = "0.0.0.0/0"