diff --git a/app/comp/moy_ue.py b/app/comp/moy_ue.py
index b0a534e5..84a7e2bf 100644
--- a/app/comp/moy_ue.py
+++ b/app/comp/moy_ue.py
@@ -266,6 +266,8 @@ def compute_ue_moys_apc(
     )
     # Annule les coefs des modules NaN
     modimpl_coefs_etuds_no_nan = np.where(np.isnan(sem_cube), 0.0, modimpl_coefs_etuds)
+    if modimpl_coefs_etuds_no_nan.dtype == np.object:  # arrive sur des tableaux vides
+        modimpl_coefs_etuds_no_nan = modimpl_coefs_etuds_no_nan.astype(np.float)
     #
     # Version vectorisée
     #
@@ -348,7 +350,8 @@ def compute_ue_moys_classic(
     modimpl_coefs_etuds_no_nan = np.where(
         np.isnan(sem_matrix), 0.0, modimpl_coefs_etuds
     )
-
+    if modimpl_coefs_etuds_no_nan.dtype == np.object:  # arrive sur des tableaux vides
+        modimpl_coefs_etuds_no_nan = modimpl_coefs_etuds_no_nan.astype(np.float)
     # ---------------------  Calcul des moyennes d'UE
     ue_modules = np.array(
         [[m.module.ue == ue for m in formsemestre.modimpls_sorted] for ue in ues]
@@ -358,6 +361,8 @@ def compute_ue_moys_classic(
     )
     # nb_ue x nb_etuds x nb_mods : coefs prenant en compte NaN et inscriptions
     coefs = (modimpl_coefs_etuds_no_nan_stacked * ue_modules).swapaxes(1, 2)
+    if coefs.dtype == np.object:  # arrive sur des tableaux vides
+        coefs = coefs.astype(np.float)
     with np.errstate(invalid="ignore"):  # ignore les 0/0 (-> NaN)
         etud_moy_ue = (
             np.sum(coefs * sem_matrix_inscrits, axis=2) / np.sum(coefs, axis=2)