diff --git a/gestioCOF/settings/common.py b/gestioCOF/settings/common.py
index fc9f1def..52aaf103 100644
--- a/gestioCOF/settings/common.py
+++ b/gestioCOF/settings/common.py
@@ -192,7 +192,7 @@ CAS_EMAIL_FORMAT = "%s@clipper.ens.fr"
 
 AUTHENTICATION_BACKENDS = (
     'django.contrib.auth.backends.ModelBackend',
-    'gestion.shared.COFCASBackend',
+    'gestion.backends.COFCASBackend',
     'kfet.auth.backends.GenericBackend',
 )
 
diff --git a/gestion/shared.py b/gestion/shared.py
deleted file mode 100644
index 39bc5da7..00000000
--- a/gestion/shared.py
+++ /dev/null
@@ -1,27 +0,0 @@
-"""
-Locking/unlocking tools to prevent tables to be corrupted
-"""
-
-from django.db import connection
-
-
-def lock_table(*models):
-    query = "LOCK TABLES "
-    for i, model in enumerate(models):
-        table = model._meta.db_table
-        if i > 0:
-            query += ", "
-        query += "%s WRITE" % table
-    cursor = connection.cursor()
-    cursor.execute(query)
-    row = cursor.fetchone()
-    return row
-
-
-def unlock_tables(*models):
-    cursor = connection.cursor()
-    cursor.execute("UNLOCK TABLES")
-    row = cursor.fetchone()
-    return row
-
-unlock_table = unlock_tables