diff --git a/test/test_mifare_desfire_ev1_aes.c b/test/test_mifare_desfire_ev1_aes.c
index 676250b..42218c8 100644
--- a/test/test_mifare_desfire_ev1_aes.c
+++ b/test/test_mifare_desfire_ev1_aes.c
@@ -651,7 +651,7 @@ test_mifare_desfire_ev1_aes (void)
 
     for (int transaction = 0; transaction < 50; transaction++) {
 	char data_buffer[100];
-	char read_buffer[100+20]; // XXX
+	char read_buffer[100];
 
 	uint8_t cs = transaction % 3;
 	if (cs == 2) cs++;