diff --git a/pyCryptomusAPI/tests.py b/pyCryptomusAPI/tests.py
index 2b869f9..8aed3a3 100644
--- a/pyCryptomusAPI/tests.py
+++ b/pyCryptomusAPI/tests.py
@@ -44,7 +44,7 @@ def test_api_functions():
     invoice = run_and_print(lambda: client.create_invoice(1, "USDT", str(uuid.uuid4())))
     wallet = run_and_print(lambda: client.create_wallet("TRON", "TRX", str(uuid.uuid4())))
     run_and_print(lambda: client.block_wallet(wallet_uuid = (wallet.uuid if wallet else "123")))                         # Server error (reason unknown)
-    run_and_print(lambda: client.block_wallet_refund(wallet.address, wallet_uuid = (wallet.uuid if wallet else "123")))  # Server error (it's ok)
+    run_and_print(lambda: client.block_wallet_refund((wallet.address if wallet else "123"), wallet_uuid = (wallet.uuid if wallet else "123")))  # Server error (it's ok)
     run_and_print(lambda: client.payment_information(invoice_uuid=(invoice.uuid if invoice else "123")))
     run_and_print(lambda: client.refund((wallet.address if wallet else "123"), True, invoice_uuid=(invoice.uuid if invoice else "123")))        # Server error (looks ok)
     run_and_print(lambda: client.payment_services())