diff --git a/imio_teleservices_templatetags/templatetags/imio_teleservices.py b/imio_teleservices_templatetags/templatetags/imio_teleservices.py
index 940c032..542d8c9 100644
--- a/imio_teleservices_templatetags/templatetags/imio_teleservices.py
+++ b/imio_teleservices_templatetags/templatetags/imio_teleservices.py
@@ -79,7 +79,7 @@ def get_birthday_from_nn(numero_national):
     numero_national : (str) numero national peut contenir espace . et -
     return : (datetime) la date de naissance
     """
-    numero_national = clean_string(numero_national)
+    numero_national = clean_string(unlazy(numero_national))
     date = numero_national[:6]
     birthday = datetime.datetime.strptime(date, "%y%m%d")
     if birthday > datetime.datetime.now():