diff --git a/app/auth/models.py b/app/auth/models.py
index 32768df03d..329bc38683 100644
--- a/app/auth/models.py
+++ b/app/auth/models.py
@@ -76,7 +76,9 @@ class User(UserMixin, db.Model):
         "Departement",
         foreign_keys=[Departement.acronym],
         primaryjoin=(dept == Departement.acronym),
-        lazy="dynamic",
+        lazy="select",
+        passive_deletes="all",
+        uselist=False,
     )
 
     def __init__(self, **kwargs):
@@ -236,7 +238,7 @@ class User(UserMixin, db.Model):
     def get_dept_id(self) -> int:
         "returns user's department id, or None"
         if self.dept:
-            return self._departement.first().id
+            return self._departement.id
         return None
 
     # Permissions management:
diff --git a/scodoc.py b/scodoc.py
index 28dfe7cfee..5b76ccb0e3 100755
--- a/scodoc.py
+++ b/scodoc.py
@@ -14,6 +14,8 @@ import click
 import flask
 from flask.cli import with_appcontext
 from flask.templating import render_template
+import psycopg2
+import sqlalchemy
 
 from app import create_app, cli, db
 from app import initialize_scodoc_database
@@ -133,11 +135,11 @@ def user_create(username, role, dept, nom=None, prenom=None):  # user-create
     "Create a new user"
     r = Role.get_named_role(role)
     if not r:
-        sys.stderr.write("user_create: role {r} does not exist\n".format(r=role))
+        sys.stderr.write(f"user_create: role {role} does not exist\n")
         return 1
     u = User.query.filter_by(user_name=username).first()
     if u:
-        sys.stderr.write("user_create: user {u} already exists\n".format(u=u))
+        sys.stderr.write(f"user_create: user {u} already exists\n")
         return 2
     if dept == "@all":
         dept = None
@@ -145,11 +147,26 @@ def user_create(username, role, dept, nom=None, prenom=None):  # user-create
     u.add_role(r, dept)
     db.session.add(u)
     db.session.commit()
-    click.echo(
-        "created user, login: {u.user_name}, with role {r} in dept. {dept}".format(
-            u=u, r=r, dept=dept
+    click.echo(f"created user, login: {u.user_name}, with role {r} in dept. {dept}")
+
+
+@app.cli.command()
+@click.argument("username")
+def user_delete(username):  # user-delete
+    "Try to delete this user. Fails if it's associated to some scodoc objects."
+    u = User.query.filter_by(user_name=username).first()
+    if not u:
+        sys.stderr.write(f"user_delete: user {username} not found\n")
+        return 2
+    db.session.delete(u)
+    try:
+        db.session.commit()
+    except (sqlalchemy.exc.IntegrityError, psycopg2.errors.ForeignKeyViolation):
+        sys.stderr.write(
+            f"""\nuser_delete: ne peux pas supprimer l'utilisateur {username}\ncar il est associé à des objets dans ScoDoc (modules, notes, ...).\n"""
         )
-    )
+        return 1
+    click.echo(f"deleted user, login: {username}")
 
 
 @app.cli.command()
@@ -485,6 +502,7 @@ def recursive_help(cmd, parent=None):
 
 @app.cli.command()
 def dumphelp():
+    """Génère la page d'aide complète pour la doc."""
     recursive_help(app.cli)