diff --git a/app/comp/bonus_spo.py b/app/comp/bonus_spo.py
index 60361c32..7ea12597 100644
--- a/app/comp/bonus_spo.py
+++ b/app/comp/bonus_spo.py
@@ -87,6 +87,8 @@ class BonusSport:
                 for m in formsemestre.modimpls_sorted
             ]
         )
+        if not len(modimpl_mask):
+            modimpl_mask = np.s_[:]  # il n'y a rien, on prend tout donc rien
         self.modimpls_spo = [
             modimpl
             for i, modimpl in enumerate(formsemestre.modimpls_sorted)
@@ -134,9 +136,12 @@ class BonusSport:
                 modimpl_inscr_spo, sem_modimpl_moys_no_nan, 0.0
             )
             modimpl_coefs_spo = modimpl_coefs_spo.T
-            modimpl_coefs_etuds = np.where(
-                modimpl_inscr_spo, np.stack([modimpl_coefs_spo] * nb_etuds), 0.0
-            )
+            if nb_etuds == 0:
+                modimpl_coefs_etuds = modimpl_inscr_spo  # vide
+            else:
+                modimpl_coefs_etuds = np.where(
+                    modimpl_inscr_spo, np.stack([modimpl_coefs_spo] * nb_etuds), 0.0
+                )
         # Annule les coefs des modules NaN (nb_etuds x nb_mod_sport)
         modimpl_coefs_etuds_no_nan = np.where(
             np.isnan(sem_modimpl_moys_spo), 0.0, modimpl_coefs_etuds
diff --git a/app/comp/moy_ue.py b/app/comp/moy_ue.py
index 8a8057ac..1d50edc1 100644
--- a/app/comp/moy_ue.py
+++ b/app/comp/moy_ue.py
@@ -310,6 +310,15 @@ def compute_ue_moys_classic(
         les coefficients effectifs de chaque UE pour chaque étudiant
         (sommes de coefs de modules pris en compte)
     """
+    if not len(modimpl_mask):  # aucun module
+        # etud_moy_gen_s, etud_moy_ue_df, etud_coef_ue_df
+        return (
+            pd.Series(
+                [0.0] * len(modimpl_inscr_df.index), index=modimpl_inscr_df.index
+            ),
+            pd.DataFrame(),
+            pd.DataFrame(),
+        )
     # Restreint aux modules sélectionnés:
     sem_matrix = sem_matrix[:, modimpl_mask]
     modimpl_inscr = modimpl_inscr_df.values[:, modimpl_mask]
@@ -415,8 +424,9 @@ def compute_malus(
                     for m in formsemestre.modimpls_sorted
                 ]
             )
-            malus_moys = sem_modimpl_moys[:, modimpl_mask].sum(axis=1)
-            malus[ue.id] = malus_moys
+            if len(modimpl_mask):
+                malus_moys = sem_modimpl_moys[:, modimpl_mask].sum(axis=1)
+                malus[ue.id] = malus_moys
 
     malus.fillna(0.0, inplace=True)
     return malus
diff --git a/app/comp/res_classic.py b/app/comp/res_classic.py
index 0d8f3242..0a892f4b 100644
--- a/app/comp/res_classic.py
+++ b/app/comp/res_classic.py
@@ -209,6 +209,8 @@ def notes_sem_assemble_matrix(modimpls_notes: list[pd.Series]) -> np.ndarray:
                      (Series rendus par compute_module_moy, index: etud)
     Resultat: ndarray (etud x module)
     """
+    if not len(modimpls_notes):
+        return np.zeros((0, 0), dtype=float)
     modimpls_notes_arr = [s.values for s in modimpls_notes]
     modimpls_notes = np.stack(modimpls_notes_arr)
     # passe de (mod x etud) à (etud x mod)