diff --git a/services/commtest/tests/backup_integration_test.rs b/services/commtest/tests/backup_integration_test.rs
--- a/services/commtest/tests/backup_integration_test.rs
+++ b/services/commtest/tests/backup_integration_test.rs
@@ -8,10 +8,12 @@
   auth::UserIdentity,
   backup::{LatestBackupIDResponse, UploadLogRequest},
 };
+use commtest::identity::device::register_user_device;
 use commtest::{
   service_addr,
   tools::{generate_stable_nbytes, Error},
 };
+use grpc_clients::identity::DeviceType;
 use reqwest::StatusCode;
 use std::collections::HashSet;
 use uuid::Uuid;
@@ -20,10 +22,12 @@
 async fn backup_integration_test() -> Result<(), Error> {
   let backup_client = BackupClient::new(service_addr::BACKUP_SERVICE_HTTP)?;
 
+  let device_info = register_user_device(None, Some(DeviceType::Ios)).await;
+
   let user_identity = UserIdentity {
-    user_id: "1".to_string(),
-    access_token: "dummy access token".to_string(),
-    device_id: "dummy device_id".to_string(),
+    user_id: device_info.user_id.clone(),
+    access_token: device_info.access_token,
+    device_id: device_info.device_id,
   };
 
   let backup_datas = generate_backup_data();
@@ -74,7 +78,7 @@
   // Test latest backup lookup
   let latest_backup_descriptor = BackupDescriptor::Latest {
     // Initial version of the backup service uses `user_id` in place of a username
-    username: "1".to_string(),
+    username: device_info.user_id.to_string(),
   };
 
   let backup_id_response = backup_client
diff --git a/services/commtest/tests/backup_performance_test.rs b/services/commtest/tests/backup_performance_test.rs
--- a/services/commtest/tests/backup_performance_test.rs
+++ b/services/commtest/tests/backup_performance_test.rs
@@ -3,10 +3,12 @@
 };
 use bytesize::ByteSize;
 use comm_lib::{auth::UserIdentity, backup::LatestBackupIDResponse};
+use commtest::identity::device::register_user_device;
 use commtest::{
   service_addr,
   tools::{generate_stable_nbytes, obtain_number_of_threads, Error},
 };
+use grpc_clients::identity::DeviceType;
 use tokio::{runtime::Runtime, task::JoinSet};
 
 #[tokio::test]
@@ -39,16 +41,19 @@
     });
   }
 
+  let device_info_1 = register_user_device(None, Some(DeviceType::Ios)).await;
+  let device_info_2 = register_user_device(None, Some(DeviceType::Ios)).await;
+
   let user_identities = [
     UserIdentity {
-      user_id: "1".to_string(),
-      access_token: "dummy access token".to_string(),
-      device_id: "dummy device_id".to_string(),
+      user_id: device_info_1.user_id.clone(),
+      access_token: device_info_1.access_token,
+      device_id: device_info_1.device_id,
     },
     UserIdentity {
-      user_id: "2".to_string(),
-      access_token: "dummy access token".to_string(),
-      device_id: "dummy device_id".to_string(),
+      user_id: device_info_2.user_id.clone(),
+      access_token: device_info_2.access_token,
+      device_id: device_info_2.device_id,
     },
   ];