diff --git a/pkg/ueps/packet_test.go b/pkg/ueps/packet_test.go
index 06ab11e..c8d235e 100644
--- a/pkg/ueps/packet_test.go
+++ b/pkg/ueps/packet_test.go
@@ -1,6 +1,7 @@
 package ueps
 
 import (
+	"bufio"
 	"bytes"
 	"testing"
 )
@@ -117,7 +118,9 @@ func TestPacket_MarshalAndSign_Bad(t *testing.T) {
 }
 
 // frame, _ := builder.MarshalAndSign(secret)
-// corrupted[len(frame)-1] ^= 0xFF // modifying any byte breaks HMAC verification
+// corrupted[len(frame)-1] ^= 0xFF
+// _, err := ReadAndVerify(bufio.NewReader(bytes.NewReader(corrupted)), secret)
+// // err == errIntegrityViolation (HMAC mismatch detected)
 func TestPacket_MarshalAndSign_Ugly(t *testing.T) {
 	builder := NewBuilder(0x03, []byte("sensitive"))
 	sharedSecret := []byte("my-secret")
@@ -132,8 +135,9 @@ func TestPacket_MarshalAndSign_Ugly(t *testing.T) {
 	copy(corrupted, frame)
 	corrupted[len(corrupted)-1] ^= 0xFF
 
-	if bytes.Equal(frame, corrupted) {
-		t.Error("expected corrupted frame to differ from original")
+	_, verifyError := ReadAndVerify(bufio.NewReader(bytes.NewReader(corrupted)), sharedSecret)
+	if verifyError == nil {
+		t.Error("expected HMAC integrity violation for corrupted frame, got nil")
 	}
 }