diff --git a/services/commtest/src/identity/device.rs b/services/commtest/src/identity/device.rs
--- a/services/commtest/src/identity/device.rs
+++ b/services/commtest/src/identity/device.rs
@@ -65,7 +65,7 @@
   let example_payload = serde_json::to_string(&device_keys)
     .expect("Failed to serialize example payload");
   // The ed25519 value from the olm payload
-  let device_id = &device_keys.primary_identity_public_keys.ed25519;
+  let device_id = device_keys.device_id();
   let device_type = device_type.unwrap_or(DeviceType::Keyserver);
 
   let mut client_registration = Registration::new();
@@ -147,7 +147,7 @@
   let example_payload = serde_json::to_string(&device_keys)
     .expect("Failed to serialize example payload");
   // The ed25519 value from the olm payload
-  let device_id = &device_keys.primary_identity_public_keys.ed25519;
+  let device_id = device_keys.device_id();
   let device_type = device_type.unwrap_or(DeviceType::Keyserver);
 
   let mut client_login = Login::new();
diff --git a/services/commtest/src/identity/olm_account_infos.rs b/services/commtest/src/identity/olm_account_infos.rs
--- a/services/commtest/src/identity/olm_account_infos.rs
+++ b/services/commtest/src/identity/olm_account_infos.rs
@@ -31,8 +31,8 @@
     }
   }
 
-  pub fn device_id(&self) -> String {
-    self.primary_identity_public_keys.ed25519.clone()
+  pub fn device_id(&self) -> &str {
+    &self.primary_identity_public_keys.ed25519
   }
 }
 
diff --git a/services/commtest/tests/identity_device_list_tests.rs b/services/commtest/tests/identity_device_list_tests.rs
--- a/services/commtest/tests/identity_device_list_tests.rs
+++ b/services/commtest/tests/identity_device_list_tests.rs
@@ -177,7 +177,7 @@
   let first_update: DeviceListHistoryItem = {
     let update_payload =
       SignedDeviceList::from_raw_unsigned(&RawDeviceList::new(vec![
-        primary_device_id.clone(),
+        primary_device_id.to_string(),
         "device2".to_string(),
       ]));
     let update_request = UpdateDeviceListRequest::from(&update_payload);
@@ -195,7 +195,7 @@
   // now perform a update (remove a device), but sign the device list
   let second_update: DeviceListHistoryItem = {
     let update_payload = SignedDeviceList::create_signed(
-      &RawDeviceList::new(vec![primary_device_id.clone()]),
+      &RawDeviceList::new(vec![primary_device_id.to_string()]),
       &mut primary_account,
       None,
     );
@@ -215,7 +215,7 @@
   {
     let mut update_payload = SignedDeviceList::create_signed(
       &RawDeviceList::new(vec![
-        primary_device_id.clone(),
+        primary_device_id.to_string(),
         "device3".to_string(),
       ]),
       &mut primary_account,
@@ -240,7 +240,7 @@
     get_device_list_history(&mut auth_client, &user.user_id).await;
 
   let expected_devices_lists: Vec<DeviceListHistoryItem> = vec![
-    (None, vec![primary_device_id.clone()]), // auto-generated during registration
+    (None, vec![primary_device_id.to_string()]), // auto-generated during registration
     first_update,
     second_update,
   ];
@@ -385,7 +385,7 @@
   // create signing account
   let mut primary_account = SigningCapableAccount::new();
   let primary_device_keys = primary_account.public_keys();
-  let primary_device_id = primary_device_keys.device_id();
+  let primary_device_id = primary_device_keys.device_id().to_string();
 
   // create initial device list
   let raw_device_list = RawDeviceList::new(vec![primary_device_id]);