diff --git a/app/scodoc/sco_utils.py b/app/scodoc/sco_utils.py
index 2a56cacfdac0432dafc91888a03bdb05c99af888..8cee570742507b0b4f371b4b5c0071f45531147e 100644
--- a/app/scodoc/sco_utils.py
+++ b/app/scodoc/sco_utils.py
@@ -402,8 +402,11 @@ class NonWorkDays(int, BiDirectionalEnum):
 
         return [
             cls.get(day.strip())
-            for day in sco_preferences.get_preference(
-                "non_travail", formsemestre_id=formsemestre_id, dept_id=dept_id
+            for day in (
+                sco_preferences.get_preference(
+                    "non_travail", formsemestre_id=formsemestre_id, dept_id=dept_id
+                )
+                or ""
             ).split(",")
         ]
 
diff --git a/app/views/assiduites.py b/app/views/assiduites.py
index 9090ec4f8c91eda20d7451858adcb0c89a64f571..70cf79dc4ad8f4fb29d88ed2f9863effff2012d1 100644
--- a/app/views/assiduites.py
+++ b/app/views/assiduites.py
@@ -2008,7 +2008,7 @@ def signal_assiduites_hebdo():
         ],
     }
 
-    non_travail = sco_preferences.get_preference("non_travail")
+    non_travail = sco_preferences.get_preference("non_travail") or ""
     non_travail = non_travail.replace(" ", "").split(",")
 
     hebdo_jours: list[tuple[bool, str]] = []
@@ -2345,7 +2345,7 @@ def feuille_abs_hebdo():
         ],
     }
 
-    non_travail = sco_preferences.get_preference("non_travail")
+    non_travail = sco_preferences.get_preference("non_travail") or ""
     non_travail = non_travail.replace(" ", "").split(",")
 
     hebdo_jours: list[tuple[bool, str]] = []
@@ -3002,7 +3002,7 @@ def _non_work_days() -> str:
     """Abbréviation des jours non travaillés: "'sam','dim'".
     donnés par les préférences du département
     """
-    non_travail = sco_preferences.get_preference("non_travail")
+    non_travail = sco_preferences.get_preference("non_travail") or ""
     non_travail = non_travail.replace(" ", "").split(",")
     return ",".join([f"'{i.lower()}'" for i in non_travail])