diff --git a/tools/testing/tests/u2f.py b/tools/testing/tests/u2f.py
index d1e8033..367ee4a 100644
--- a/tools/testing/tests/u2f.py
+++ b/tools/testing/tests/u2f.py
@@ -42,12 +42,14 @@ class U2FTests(Tester):
         with Test("Check bad INS"):
             try:
                 self.ctap1.send_apdu(0, 0, 0, 0, b"")
+                assert False
             except ApduError as e:
                 assert e.code == 0x6D00
 
         with Test("Check bad CLA"):
             try:
                 self.ctap1.send_apdu(1, CTAP1.INS.VERSION, 0, 0, b"abc")
+                assert False
             except ApduError as e:
                 assert e.code == 0x6E00