diff --git a/app/views/users.py b/app/views/users.py
index 1d6a0f70..01c30277 100644
--- a/app/views/users.py
+++ b/app/views/users.py
@@ -397,9 +397,12 @@ def create_user_form(REQUEST, user_name=None, edit=0):
                 del vals["status"]  # no one can't change its own status
             if "date_expiration" in vals:
                 try:
-                    vals["date_expiration"] = datetime.datetime.strptime(
-                        vals["date_expiration"], "%d/%m/%Y"
-                    )
+                    if vals["date_expiration"]:
+                        vals["date_expiration"] = datetime.datetime.strptime(
+                            vals["date_expiration"], "%d/%m/%Y"
+                        )
+                    else:
+                        vals["date_expiration"] = None
                 except ValueError:
                     H.append(tf_error_message("date expiration invalide"))
                     return "\n".join(H) + "\n" + tf[1] + F