diff --git a/modules/project/README.md b/modules/project/README.md
index 01a5c5fff..ebb7a5521 100644
--- a/modules/project/README.md
+++ b/modules/project/README.md
@@ -2267,27 +2267,27 @@ module "project" {
 | [custom_role_id](outputs.tf#L33) | Map of custom role IDs created in the project. |  |
 | [custom_roles](outputs.tf#L38) | Map of custom roles resources created in the project. |  |
 | [default_service_accounts](outputs.tf#L43) | Emails of the default service accounts for this project. |  |
-| [id](outputs.tf#L51) | Project id. |  |
-| [kms_autokeys](outputs.tf#L69) | KMS Autokey key ids. |  |
-| [name](outputs.tf#L76) | Project name. |  |
-| [network_tag_keys](outputs.tf#L88) | Tag key resources. |  |
-| [network_tag_values](outputs.tf#L97) | Tag value resources. |  |
-| [notification_channel_names](outputs.tf#L105) | Notification channel names. |  |
-| [notification_channels](outputs.tf#L113) | Full notification channel objects. |  |
-| [number](outputs.tf#L118) | Project number. |  |
-| [organization_policies_ids](outputs.tf#L133) | Map of ORGANIZATION_POLICIES => ID in the organization. |  |
-| [project_id](outputs.tf#L140) | Project id. |  |
-| [quota_configs](outputs.tf#L158) | Quota configurations. |  |
-| [quotas](outputs.tf#L169) | Quota resources. |  |
-| [scc_custom_sha_modules_ids](outputs.tf#L174) | Map of SCC CUSTOM SHA MODULES => ID in the project. |  |
-| [service_agents](outputs.tf#L179) | List of all (active) service agents for this project. |  |
-| [services](outputs.tf#L188) | Service APIs to enable in the project. |  |
-| [sink_writer_identities](outputs.tf#L197) | Writer identities created for each sink. |  |
-| [tag_keys](outputs.tf#L204) | Tag key resources. |  |
-| [tag_values](outputs.tf#L213) | Tag value resources. |  |
-| [workload_identity_pool_ids](outputs.tf#L221) | Workload identity provider ids. |  |
-| [workload_identity_provider_ids](outputs.tf#L228) | Workload identity provider attributes. |  |
-| [workload_identity_providers](outputs.tf#L236) | Workload identity provider attributes. |  |
+| [id](outputs.tf#L48) | Project id. |  |
+| [kms_autokeys](outputs.tf#L66) | KMS Autokey key ids. |  |
+| [name](outputs.tf#L73) | Project name. |  |
+| [network_tag_keys](outputs.tf#L85) | Tag key resources. |  |
+| [network_tag_values](outputs.tf#L94) | Tag value resources. |  |
+| [notification_channel_names](outputs.tf#L102) | Notification channel names. |  |
+| [notification_channels](outputs.tf#L110) | Full notification channel objects. |  |
+| [number](outputs.tf#L115) | Project number. |  |
+| [organization_policies_ids](outputs.tf#L130) | Map of ORGANIZATION_POLICIES => ID in the organization. |  |
+| [project_id](outputs.tf#L137) | Project id. |  |
+| [quota_configs](outputs.tf#L155) | Quota configurations. |  |
+| [quotas](outputs.tf#L166) | Quota resources. |  |
+| [scc_custom_sha_modules_ids](outputs.tf#L171) | Map of SCC CUSTOM SHA MODULES => ID in the project. |  |
+| [service_agents](outputs.tf#L176) | List of all (active) service agents for this project. |  |
+| [services](outputs.tf#L185) | Service APIs to enable in the project. |  |
+| [sink_writer_identities](outputs.tf#L194) | Writer identities created for each sink. |  |
+| [tag_keys](outputs.tf#L201) | Tag key resources. |  |
+| [tag_values](outputs.tf#L210) | Tag value resources. |  |
+| [workload_identity_pool_ids](outputs.tf#L218) | Workload identity provider ids. |  |
+| [workload_identity_provider_ids](outputs.tf#L225) | Workload identity provider attributes. |  |
+| [workload_identity_providers](outputs.tf#L233) | Workload identity provider attributes. |  |
 
 ## Fixtures
 
diff --git a/modules/project/outputs.tf b/modules/project/outputs.tf
index 2ce6ceae5..1fa7b32b8 100644
--- a/modules/project/outputs.tf
+++ b/modules/project/outputs.tf
@@ -1,5 +1,5 @@
 /**
- * Copyright 2025 Google LLC
+ * Copyright 2026 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,10 +42,7 @@ output "custom_roles" {
 
 output "default_service_accounts" {
   description = "Emails of the default service accounts for this project."
-  value = {
-    compute = "${local.project.number}-compute@developer.gserviceaccount.com"
-    gae     = "${local.project.project_id}@appspot.gserviceaccount.com"
-  }
+  value       = local.default_service_accounts
 }
 
 output "id" {
diff --git a/modules/project/service-agents.tf b/modules/project/service-agents.tf
index 1a1927df1..2345eb546 100644
--- a/modules/project/service-agents.tf
+++ b/modules/project/service-agents.tf
@@ -1,5 +1,5 @@
 /**
- * Copyright 2025 Google LLC
+ * Copyright 2026 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -125,6 +125,23 @@ locals {
       try(var.project_reuse.attributes.services_enabled, [])
     )) : s if !contains(local._u_unavailable_si, s)
   ]
+
+
+  default_service_accounts = (
+    var.universe == null
+    ? {
+      compute = "${local.project.number}-compute@developer.gserviceaccount.com"
+      gae     = "${local.project.project_id}@appspot.gserviceaccount.com"
+    }
+    : {
+      compute = "${local.project.number}-compute@developer.${local._u_domain}iam.gserviceaccount.com"
+      gae = format(
+        "%s@appspot.%siam.gserviceaccount.com",
+        trimprefix(local.project.project_id, "${var.universe.prefix}:"),
+        local._u_domain
+      )
+    }
+  )
 }
 
 data "google_storage_project_service_account" "gcs_sa" {
diff --git a/tests/modules/project/service_agents_universe.yaml b/tests/modules/project/service_agents_universe.yaml
index 01c270777..867520006 100644
--- a/tests/modules/project/service_agents_universe.yaml
+++ b/tests/modules/project/service_agents_universe.yaml
@@ -1,4 +1,4 @@
-# Copyright 2025 Google LLC
+# Copyright 2026 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -76,8 +76,8 @@ values:
 
 outputs:
   default_service_accounts:
-    compute: 12345-compute@developer.gserviceaccount.com
-    gae: alpha:my-project@appspot.gserviceaccount.com
+    compute: 12345-compute@developer.alpha-system.iam.gserviceaccount.com
+    gae: my-project@appspot.alpha-system.iam.gserviceaccount.com
   id: alpha:my-project
   name: my-project
   number: 12345