diff --git a/app/mercadopago.py b/app/mercadopago.py
index 15b46a7..0bfb84a 100644
--- a/app/mercadopago.py
+++ b/app/mercadopago.py
@@ -85,8 +85,9 @@ class MercadoPagoPayment:
             body.update(token=method['token'], payment_method_id=method['payment_method_id'],
                         installments=int(method.get('installments', 1)),
                         three_d_secure_mode='optional')
-            if method.get('issuer_id'):
-                body['issuer_id'] = method['issuer_id']
+            # No issuer_id: Mercado Pago takes the issuer from the card number.
+            # The form's suggestion was refused for its own test cards
+            # (10111, "the issuer does not have the BIN configured").
         else:
             raise ValueError('Unsupported payment method')
         # A PIX retry must return the same code; a new one, after the last
diff --git a/tests/test_mercadopago.py b/tests/test_mercadopago.py
index 5f749f6..bb4854f 100644
--- a/tests/test_mercadopago.py
+++ b/tests/test_mercadopago.py
@@ -140,6 +140,9 @@ class MercadoPagoTests(unittest.TestCase):
         self.assertNotEqual(self.requests[-1].headers['x-idempotency-key'], first_key)
         self.assertTrue(first_key.startswith('dtf-quote-q-card-'))
         self.assertEqual(body['three_d_secure_mode'], 'optional')
+        self.mp.create('q', 1000, {'mail': 'a@example.test', 'cnpj': '11222333000181'},
+                       {'type': 'card', 'token': 'tok_iss', 'payment_method_id': 'master', 'issuer_id': '24'})
+        self.assertNotIn('issuer_id', json.loads(self.requests[-1].content))
         self.assertIsNone(self.mp.create('q', 1000, {'mail': 'a@example.test', 'cnpj': '11222333000181'},
                                          {'type': 'card', 'token': 'tok_ghi', 'payment_method_id': 'visa'})['challenge'])