diff --git a/fractal_server/app/routes/api/v1/_aux_functions.py b/fractal_server/app/routes/api/v1/_aux_functions.py
index f807276be..0535cdab7 100644
--- a/fractal_server/app/routes/api/v1/_aux_functions.py
+++ b/fractal_server/app/routes/api/v1/_aux_functions.py
@@ -368,8 +368,11 @@ async def _get_task_check_owner(
                 ),
             )
         else:
-            verify_user_has_settings(user)
-            owner = user.username or user.settings.slurm_user
+            if user.username:
+                owner = user.username
+            else:
+                verify_user_has_settings(user)
+                owner = user.settings.slurm_user
             if owner != task.owner:
                 raise HTTPException(
                     status_code=status.HTTP_403_FORBIDDEN,
diff --git a/fractal_server/app/routes/api/v2/_aux_functions.py b/fractal_server/app/routes/api/v2/_aux_functions.py
index 9631346ea..6d114f02b 100644
--- a/fractal_server/app/routes/api/v2/_aux_functions.py
+++ b/fractal_server/app/routes/api/v2/_aux_functions.py
@@ -363,8 +363,11 @@ async def _get_task_check_owner(
                 ),
             )
         else:
-            verify_user_has_settings(user)
-            owner = user.username or user.settings.slurm_user
+            if user.username:
+                owner = user.username
+            else:
+                verify_user_has_settings(user)
+                owner = user.settings.slurm_user
             if owner != task.owner:
                 raise HTTPException(
                     status_code=status.HTTP_403_FORBIDDEN,
diff --git a/fractal_server/app/routes/api/v2/task_collection_custom.py b/fractal_server/app/routes/api/v2/task_collection_custom.py
index 3b242ded8..fcbe03b2b 100644
--- a/fractal_server/app/routes/api/v2/task_collection_custom.py
+++ b/fractal_server/app/routes/api/v2/task_collection_custom.py
@@ -113,8 +113,11 @@ async def collect_task_custom(
         package_root = Path(task_collect.package_root)
 
     # Set task.owner attribute
-    verify_user_has_settings(user)
-    owner = user.username or user.settings.slurm_user
+    if user.username:
+        owner = user.username
+    else:
+        verify_user_has_settings(user)
+        owner = user.settings.slurm_user
     if owner is None:
         raise HTTPException(
             status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,