diff --git a/app/decorators.py b/app/decorators.py
index 83441275..5338828f 100644
--- a/app/decorators.py
+++ b/app/decorators.py
@@ -16,6 +16,7 @@ import flask_login
 import app
 from app.auth.models import User
 import app.scodoc.sco_utils as scu
+from app.scodoc.sco_exceptions import ScoValueError
 
 
 class ZUser(object):
@@ -180,19 +181,24 @@ def scodoc7func(func):
         else:
             arg_names = argspec.args
         for arg_name in arg_names:  # pour chaque arg de la fonction vue
-            if arg_name == "REQUEST":  # ne devrait plus arriver !
-                # debug check, TODO remove after tests
-                raise ValueError("invalid REQUEST parameter !")
-            else:
-                # peut produire une KeyError s'il manque un argument attendu:
-                v = req_args[arg_name]
-                # try to convert all arguments to INTEGERS
-                # necessary for db ids and boolean values
-                try:
-                    v = int(v)
-                except (ValueError, TypeError):
-                    pass
-                pos_arg_values.append(v)
+            # peut produire une KeyError s'il manque un argument attendu:
+            v = req_args[arg_name]
+            # try to convert all arguments to INTEGERS
+            # necessary for db ids and boolean values
+            try:
+                v = int(v) if v else v
+            except (ValueError, TypeError) as exc:
+                if arg_name in {
+                    "etudid",
+                    "formation_id",
+                    "formsemestre_id",
+                    "module_id",
+                    "moduleimpl_id",
+                    "partition_id",
+                    "ue_id",
+                }:
+                    raise ScoValueError("page introuvable (id invalide)") from exc
+            pos_arg_values.append(v)
         # current_app.logger.info("pos_arg_values=%s" % pos_arg_values)
         # current_app.logger.info("req_args=%s" % req_args)
         # Add keyword arguments