diff --git a/configure.ac b/configure.ac
index b0473a8..37874bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -132,3 +132,5 @@ AC_CONFIG_FILES([
 		])
 
 AC_OUTPUT
+
+LIBNFC_DRIVERS_SUMMARY
diff --git a/libnfc/drivers/Makefile.am b/libnfc/drivers/Makefile.am
index 79bd5bc..3aff81f 100644
--- a/libnfc/drivers/Makefile.am
+++ b/libnfc/drivers/Makefile.am
@@ -3,16 +3,39 @@ INCLUDES= $(all_includes) $(LIBNFC_CFLAGS)
 
 noinst_HEADERS = acr122.h arygon.h pn531_usb.h pn532_uart.h pn533_usb.h pn53x_usb.h
 noinst_LTLIBRARIES = libnfcdrivers.la
-libnfcdrivers_la_SOURCES = acr122.c arygon.c pn531_usb.c pn532_uart.c pn533_usb.c pn53x_usb.c
+
+libnfcdrivers_la_SOURCES = 
 libnfcdrivers_la_CFLAGS = @DRIVERS_CFLAGS@ -I$(top_srcdir)/libnfc -I$(top_srcdir)/libnfc/buses
 libnfcdrivers_la_LIBADD = 
 
+if DRIVER_ACR122_ENABLED
+libnfcdrivers_la_SOURCES += acr122.c
+endif
+
+if DRIVER_ARYGON_ENABLED
+libnfcdrivers_la_SOURCES += arygon.c
+endif
+
+if DRIVER_PN531_USB_ENABLED
+libnfcdrivers_la_SOURCES += pn531_usb.c
+endif
+
+if DRIVER_PN533_USB_ENABLED
+libnfcdrivers_la_SOURCES += pn533_usb.c
+endif
+
+
+if DRIVER_PN532_UART_ENABLED
+libnfcdrivers_la_SOURCES += pn532_uart.c
+endif
+
 if PCSC_ENABLED
   libnfcdrivers_la_CFLAGS += @libpcsclite_CFLAGS@
   libnfcdrivers_la_LIBADD += @libpcsclite_LIBS@
 endif
 
 if LIBUSB_ENABLED
+  libnfcdrivers_la_SOURCES += pn53x_usb.c
   libnfcdrivers_la_CFLAGS += @libusb_CFLAGS@
   libnfcdrivers_la_LIBADD  += @libusb_LIBS@
 endif
diff --git a/libnfc/drivers/acr122.c b/libnfc/drivers/acr122.c
index 47357e8..4b94db8 100644
--- a/libnfc/drivers/acr122.c
+++ b/libnfc/drivers/acr122.c
@@ -22,8 +22,6 @@
  * @brief Driver for ACR122 devices (e.g. Tikitag, Touchatag, ACS ACR122)
  */
 
-#ifdef DRIVER_ACR122_ENABLED
-
 #ifdef HAVE_CONFIG_H
   #include "config.h"
 #endif // HAVE_CONFIG_H
@@ -360,5 +358,3 @@ bool acr122_led_red(const nfc_device_spec_t nds, bool bOn)
   }
 }
 
-#endif // DRIVER_ACR122_ENABLED
-
diff --git a/libnfc/drivers/arygon.c b/libnfc/drivers/arygon.c
index 2d5fbd6..8c43f21 100644
--- a/libnfc/drivers/arygon.c
+++ b/libnfc/drivers/arygon.c
@@ -25,8 +25,6 @@
  * UART connection can be direct (host<->arygon_uc) or could be provided by internal USB to serial interface (e.g. host<->ftdi_chip<->arygon_uc)
  */
 
-#ifdef DRIVER_ARYGON_ENABLED
-
 #ifdef HAVE_CONFIG_H
   #include "config.h"
 #endif // HAVE_CONFIG_H
@@ -331,5 +329,3 @@ arygon_check_communication(const nfc_device_spec_t nds)
   return true;
 }
 
-#endif // DRIVER_ARYGON_ENABLED
-
diff --git a/libnfc/drivers/pn531_usb.c b/libnfc/drivers/pn531_usb.c
index 274af28..2386245 100644
--- a/libnfc/drivers/pn531_usb.c
+++ b/libnfc/drivers/pn531_usb.c
@@ -26,8 +26,6 @@
 Thanks to d18c7db and Okko for example code
 */
 
-#ifdef DRIVER_PN531_USB_ENABLED
-
 #ifdef HAVE_CONFIG_H
   #include "config.h"
 #endif // HAVE_CONFIG_H
@@ -73,5 +71,3 @@ nfc_device_t* pn531_usb_connect(const nfc_device_desc_t* pndd)
   return pn53x_usb_connect(pndd, pndd->acDevice, NC_PN531);
 }
 
-#endif // DRIVER_PN531_USB_ENABLED
-
diff --git a/libnfc/drivers/pn532_uart.c b/libnfc/drivers/pn532_uart.c
index 334671e..26c89a0 100644
--- a/libnfc/drivers/pn532_uart.c
+++ b/libnfc/drivers/pn532_uart.c
@@ -22,8 +22,6 @@
  * @brief PN532 driver using UART bus (UART, RS232, etc.)
  */
 
-#ifdef DRIVER_PN532_UART_ENABLED
-
 #ifdef HAVE_CONFIG_H
   #include "config.h"
 #endif // HAVE_CONFIG_H
@@ -339,5 +337,3 @@ pn532_uart_check_communication(const nfc_device_spec_t nds)
   return true;
 }
 
-#endif // DRIVER_PN532_UART_ENABLED
-
diff --git a/libnfc/drivers/pn533_usb.c b/libnfc/drivers/pn533_usb.c
index f18d0cf..19d6b71 100644
--- a/libnfc/drivers/pn533_usb.c
+++ b/libnfc/drivers/pn533_usb.c
@@ -26,8 +26,6 @@
 Thanks to d18c7db and Okko for example code
 */
 
-#ifdef DRIVER_PN533_USB_ENABLED
-
 #ifdef HAVE_CONFIG_H
   #include "config.h"
 #endif // HAVE_CONFIG_H
@@ -71,5 +69,3 @@ nfc_device_t* pn533_usb_connect(const nfc_device_desc_t* pndd)
   return pn53x_usb_connect(pndd, pndd->acDevice, NC_PN533);
 }
 
-#endif // DRIVER_PN533_USB_ENABLED
-
diff --git a/libnfc/drivers/pn53x_usb.c b/libnfc/drivers/pn53x_usb.c
index 1fd9d39..b0f3d96 100644
--- a/libnfc/drivers/pn53x_usb.c
+++ b/libnfc/drivers/pn53x_usb.c
@@ -281,6 +281,12 @@ bool pn53x_usb_transceive(const nfc_device_spec_t nds, const byte_t* pbtTx, cons
 #ifdef DEBUG
   PRINT_HEX("RX", abtRx,ret);
 #endif
+  
+  uint8_t ack_frame[] = { 0x00, 0x00, 0xff, 0x00, 0xff, 0x00 };
+  if ((ret != 6) || (memcmp (abtRx, ack_frame, 6))) {
+      DBG ("%s", "===> No ACK!!!!!!");
+    return false;
+  }
 
   if( ret == 6 )
   {
@@ -296,6 +302,8 @@ bool pn53x_usb_transceive(const nfc_device_spec_t nds, const byte_t* pbtTx, cons
 #endif
   }
 
+  usb_bulk_write(pus->pudh, pus->uiEndPointOut, (char *)ack_frame, 6, USB_TIMEOUT);
+
   // When the answer should be ignored, just return a succesful result
   if(pbtRx == NULL || pszRxLen == NULL) return true;
 
diff --git a/m4/libnfc_drivers.m4 b/m4/libnfc_drivers.m4
index 81db849..d51883f 100644
--- a/m4/libnfc_drivers.m4
+++ b/m4/libnfc_drivers.m4
@@ -4,7 +4,7 @@ AC_DEFUN([LIBNFC_ARG_WITH_DRIVERS],
 [
   AC_MSG_CHECKING(which drivers to build)
   AC_ARG_WITH(drivers,
-  AC_HELP_STRING([[[[--with-drivers=driver@<:@,driver...@:>@]]]], [Only use specific drivers (default set)]),
+  AC_HELP_STRING([[[--with-drivers=driver@<:@,driver...@:>@]]], [Only use specific drivers (default set)]),
   [       case "${withval}" in
           yes | no)
                   dnl ignore calls without any arguments
@@ -34,25 +34,36 @@ AC_DEFUN([LIBNFC_ARG_WITH_DRIVERS],
   
   DRIVERS_CFLAGS=""
 
+  driver_acr122_enabled="no"
+  driver_pn531_usb_enabled="no"
+  driver_pn533_usb_enabled="no"
+  driver_arygon_enabled="no"
+  driver_pn532_uart_enabled="no"
+
   for driver in ${DRIVER_BUILD_LIST}
   do
     case "${driver}" in
     acr122)
                   pcsc_required="yes"
+		  driver_acr122_enabled="yes"
                   DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_ACR122_ENABLED"
                   ;;
     pn531_usb)
                   libusb_required="yes"
+		  driver_pn531_usb_enabled="yes"
                   DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN531_USB_ENABLED"
                   ;;
     pn533_usb)
                   libusb_required="yes"
+		  driver_pn533_usb_enabled="yes"
                   DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN533_USB_ENABLED"
                   ;;
     arygon)
+                  driver_arygon_enabled="yes"
                   DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_ARYGON_ENABLED"
                   ;;
     pn532_uart)
+                  driver_pn532_uart_enabled="yes"
                   DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN532_UART_ENABLED"
                   ;;
     *)
@@ -61,4 +72,19 @@ AC_DEFUN([LIBNFC_ARG_WITH_DRIVERS],
     esac
   done
   AC_SUBST(DRIVERS_CFLAGS)
+  AM_CONDITIONAL(DRIVER_ACR122_ENABLED, [test x"$driver_acr122_enabled" = xyes])
+  AM_CONDITIONAL(DRIVER_PN531_USB_ENABLED, [test x"$driver_pn531_usb_enabled" = xyes])
+  AM_CONDITIONAL(DRIVER_PN533_USB_ENABLED, [test x"$driver_pn533_usb_enabled" = xyes])
+  AM_CONDITIONAL(DRIVER_ARYGON_ENABLED, [test x"$driver_arygon_enabled" = xyes])
+  AM_CONDITIONAL(DRIVER_PN532_UART_ENABLED, [test x"$driver_pn532_uart_enabled" = xyes])
+])
+
+AC_DEFUN([LIBNFC_DRIVERS_SUMMARY],[
+echo
+echo "Selected drivers:"
+echo "   acr122........... $driver_acr122_enabled"
+echo "   arygon........... $driver_arygon_enabled"
+echo "   pn531_usb........ $driver_pn531_usb_enabled"
+echo "   pn532_uart....... $driver_pn532_uart_enabled"
+echo "   pn533_usb........ $driver_pn533_usb_enabled"
 ])