diff --git a/eopayment/paybox.py b/eopayment/paybox.py
index 90931db..472ac95 100644
--- a/eopayment/paybox.py
+++ b/eopayment/paybox.py
@@ -232,7 +232,7 @@ class Payment(PaymentCommon):
             },
             {
                 'name': 'shared_secret',
-                'caption': _('Secret partagé'),
+                'caption': _('Secret partagé (clé HMAC)'),
                 'validation': lambda x: isinstance(x, str)
                 and all(a.lower() in '0123456789ABCDEF' for a in x),
                 'required': True,