diff --git a/libnfc/chips/pn53x-internal.h b/libnfc/chips/pn53x-internal.h
index 34e6ece..1272891 100644
--- a/libnfc/chips/pn53x-internal.h
+++ b/libnfc/chips/pn53x-internal.h
@@ -112,10 +112,10 @@
  * Start bytes, packet length, length checksum, direction, packet checksum and postamble are overhead
  */
 // The TFI is considered part of the overhead
-#  define PN53x_NORMAL_FRAME__DATA_MAX_LEN		254
-#  define PN53x_NORMAL_FRAME__OVERHEAD			8
-#  define PN53x_EXTENDED_FRAME__DATA_MAX_LEN		264
-#  define PN53x_EXTENDED_FRAME__OVERHEAD		11
+#  define PN53x_NORMAL_FRAME__DATA_MAX_LEN              254
+#  define PN53x_NORMAL_FRAME__OVERHEAD                  8
+#  define PN53x_EXTENDED_FRAME__DATA_MAX_LEN            264
+#  define PN53x_EXTENDED_FRAME__OVERHEAD                11
 #  define PN53x_ACK_FRAME__LEN                          6
 
 typedef struct {
diff --git a/libnfc/chips/pn53x.h b/libnfc/chips/pn53x.h
index 51d5dbf..9688441 100644
--- a/libnfc/chips/pn53x.h
+++ b/libnfc/chips/pn53x.h
@@ -294,8 +294,8 @@ typedef enum {
   PTM_ISO14443_4_PICC_ONLY = 0x04
 } pn53x_target_mode;
 
-extern const uint8_t pn53x_ack_frame[6];
-extern const uint8_t pn53x_nack_frame[6];
+extern const uint8_t pn53x_ack_frame[PN53x_ACK_FRAME__LEN];
+extern const uint8_t pn53x_nack_frame[PN53x_ACK_FRAME__LEN];
 
 int    pn53x_init(struct nfc_device *pnd);
 int    pn53x_transceive(struct nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx, uint8_t *pbtRx, const size_t szRxLen, int timeout);
diff --git a/libnfc/drivers/arygon.c b/libnfc/drivers/arygon.c
index 59263e9..b8c832c 100644
--- a/libnfc/drivers/arygon.c
+++ b/libnfc/drivers/arygon.c
@@ -337,7 +337,7 @@ arygon_tama_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, i
     return pnd->last_error;
   }
 
-  uint8_t abtRxBuf[6];
+  uint8_t abtRxBuf[PN53x_ACK_FRAME__LEN];
   if ((res = uart_receive(DRIVER_DATA(pnd)->port, abtRxBuf, sizeof(abtRxBuf), 0, timeout)) != 0) {
     log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "Unable to read ACK");
     pnd->last_error = res;
diff --git a/libnfc/drivers/pn532_i2c.c b/libnfc/drivers/pn532_i2c.c
index bc25f35..bfd5f3e 100644
--- a/libnfc/drivers/pn532_i2c.c
+++ b/libnfc/drivers/pn532_i2c.c
@@ -337,7 +337,7 @@ pn532_i2c_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, int
   uint8_t abtRxBuf[PN53x_ACK_FRAME__LEN];
 
   // Wait for the ACK frame
-  res = pn532_i2c_wait_rdyframe(pnd, abtRxBuf, PN53x_ACK_FRAME__LEN, timeout);
+  res = pn532_i2c_wait_rdyframe(pnd, abtRxBuf, sizeof(abtRxBuf), timeout);
   if (res < 0) {
     if (res == NFC_EOPABORTED) {
       // Send an ACK frame from host to abort the command.
diff --git a/libnfc/drivers/pn532_spi.c b/libnfc/drivers/pn532_spi.c
index 639f08d..93ed75e 100644
--- a/libnfc/drivers/pn532_spi.c
+++ b/libnfc/drivers/pn532_spi.c
@@ -601,8 +601,8 @@ pn532_spi_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, int
 
 
 
-  uint8_t abtRxBuf[6];
-  res = spi_send_receive(DRIVER_DATA(pnd)->port, &pn532_spi_cmd_dataread, 1, abtRxBuf, 6, true);
+  uint8_t abtRxBuf[PN53x_ACK_FRAME__LEN];
+  res = spi_send_receive(DRIVER_DATA(pnd)->port, &pn532_spi_cmd_dataread, 1, abtRxBuf, sizeof(abtRxBuf), true);
 
   if (res != 0) {
     log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG, "%s", "Unable to read ACK");
diff --git a/libnfc/drivers/pn532_uart.c b/libnfc/drivers/pn532_uart.c
index 1f3294d..2818919 100644
--- a/libnfc/drivers/pn532_uart.c
+++ b/libnfc/drivers/pn532_uart.c
@@ -334,8 +334,8 @@ pn532_uart_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, in
     return pnd->last_error;
   }
 
-  uint8_t abtRxBuf[6];
-  res = uart_receive(DRIVER_DATA(pnd)->port, abtRxBuf, 6, 0, timeout);
+  uint8_t abtRxBuf[PN53x_ACK_FRAME__LEN];
+  res = uart_receive(DRIVER_DATA(pnd)->port, abtRxBuf, sizeof(abtRxBuf), 0, timeout);
   if (res != 0) {
     log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG, "%s", "Unable to read ACK");
     pnd->last_error = res;