diff --git a/app/scodoc/sco_preferences.py b/app/scodoc/sco_preferences.py
index dbbdd0ac..6667db96 100644
--- a/app/scodoc/sco_preferences.py
+++ b/app/scodoc/sco_preferences.py
@@ -68,17 +68,17 @@ des tuples (name, value, formsemestre_id).
 Si formsemestre_id est NULL, la valeur concerne tous les semestres,
 sinon, elle ne concerne que le semestre indiqué. 
 
-* Utilisation dans ScoDoc8
+* Utilisation dans ScoDoc 9
   - lire une valeur: 
       get_preference(name, formsemestre_id)
       nb: les valeurs sont des chaines, sauf:
-         . si le type est spécfié (float ou int)
+         . si le type est spécifié (float ou int)
          . les boolcheckbox qui sont des entiers 0 ou 1
   - avoir un mapping (read only) de toutes les valeurs:
       sco_preferences.SemPreferences(formsemestre_id)
-  - editer les preferences globales:
+  - éditer les preferences globales:
       sco_preferences.get_base_preferences(self).edit()
-  - editer les preferences d'un semestre:
+  - éditer les preferences d'un semestre:
       SemPreferences(formsemestre_id).edit()
 
 * Implémentation: sco_preferences.py
@@ -123,22 +123,22 @@ from app.scodoc.TrivialFormulator import TrivialFormulator
 import app.scodoc.notesdb as ndb
 import app.scodoc.sco_utils as scu
 
-_SCO_BASE_PREFERENCES = {}  # { dept_acronym: BasePreferences instance }
-
 
 def clear_base_preferences():
     """Clear cached preferences"""
     # usefull only for tests, where the same process may run
     # successively on several databases
-    _SCO_BASE_PREFERENCES.clear()
+    g._SCO_BASE_PREFERENCES = {}  # { dept_id: BasePreferences instance }
 
 
 def get_base_preferences():
     """Return global preferences for the current department"""
-    dept_acronym = g.scodoc_dept
-    if not dept_acronym in _SCO_BASE_PREFERENCES:
-        _SCO_BASE_PREFERENCES[dept_acronym] = BasePreferences(dept_acronym)
-    return _SCO_BASE_PREFERENCES[dept_acronym]
+    dept_id = g.scodoc_dept_id
+    if not hasattr(g, "_SCO_BASE_PREFERENCES"):
+        g._SCO_BASE_PREFERENCES = {}
+    if not dept_id in g._SCO_BASE_PREFERENCES:
+        g._SCO_BASE_PREFERENCES[dept_id] = BasePreferences(dept_id)
+    return g._SCO_BASE_PREFERENCES[dept_id]
 
 
 def get_preference(name, formsemestre_id=None):
@@ -263,10 +263,10 @@ class BasePreferences(object):
         filter_nulls=False,
     )
 
-    def __init__(self, dept_acronym: str):
-        dept = Departement.query.filter_by(acronym=dept_acronym).first()
+    def __init__(self, dept_id: int):
+        dept = Departement.query.get(dept_id)
         if not dept:
-            raise ScoValueError(f"Invalid departement: {dept_acronym}")
+            raise ScoValueError(f"Invalid departement: {dept_id}")
         self.dept_id = dept.id
         self.init()
         self.load()
diff --git a/sco_version.py b/sco_version.py
index 28aefc96..884506e9 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.1.54"
+SCOVERSION = "9.2a-54"
 
 SCONAME = "ScoDoc"