diff --git a/app/scodoc/sco_edit_ue.py b/app/scodoc/sco_edit_ue.py
index 016d8880..677c1ae4 100644
--- a/app/scodoc/sco_edit_ue.py
+++ b/app/scodoc/sco_edit_ue.py
@@ -52,7 +52,6 @@ from app.scodoc.sco_exceptions import (
 )
 
 from app.scodoc import html_sco_header
-from app.scodoc import sco_cache
 from app.scodoc import sco_codes_parcours
 from app.scodoc import sco_edit_apc
 from app.scodoc import sco_edit_matiere
@@ -188,7 +187,11 @@ def do_ue_delete(ue_id, delete_validations=False, force=False):
             "DELETE FROM scolar_formsemestre_validation WHERE ue_id=%(ue_id)s",
             {"ue_id": ue.id},
         )
-
+    # delete old formulas
+    ndb.SimpleQuery(
+        "DELETE FROM notes_formsemestre_ue_computation_expr WHERE ue_id=%(ue_id)s",
+        {"ue_id": ue.id},
+    )
     # delete all matiere in this UE
     mats = sco_edit_matiere.matiere_list({"ue_id": ue.id})
     for mat in mats: