diff --git a/modules/apigee/main.tf b/modules/apigee/main.tf
index b1f99839..85d0f175 100644
--- a/modules/apigee/main.tf
+++ b/modules/apigee/main.tf
@@ -18,7 +18,7 @@ locals {
   org_id   = try(google_apigee_organization.organization[0].id, "organizations/${var.project_id}")
   org_name = try(google_apigee_organization.organization[0].name, var.project_id)
   instance_environment_list = merge(concat([for k1, v1 in var.instances : {
-    for v2 in v1.environments :
+    for v2 in coalesce(v1.environments, []) :
     "${k1}-${v2}" => {
       environment = v2
       region      = k1
@@ -121,7 +121,7 @@ resource "google_apigee_nat_address" "apigee_nat" {
 }
 
 resource "google_apigee_instance_attachment" "instance_attachments" {
-  for_each    = local.instance_environment_list
+  for_each    = coalesce(local.instance_environment_list, local.environment_region_list)
   instance_id = google_apigee_instance.instances[each.value.region].id
   environment = try(google_apigee_environment.environments[each.value.environment].name,
   "${local.org_id}/environments/${each.value.environment}")