diff --git a/examples/nfc-emulate-tag.c b/examples/nfc-emulate-tag.c
index a6d3e5a..dda8915 100644
--- a/examples/nfc-emulate-tag.c
+++ b/examples/nfc-emulate-tag.c
@@ -35,6 +35,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
+#include <signal.h>
 
 #include <nfc/nfc.h>
 
@@ -49,6 +50,16 @@ static nfc_device_t *pnd;
 static bool quiet_output = false;
 static bool init_mfc_auth = false;
 
+void
+intr_hdlr (void)
+{
+  printf ("\nQuitting...\n");
+  if (pnd != NULL) {
+    nfc_disconnect(pnd);
+  }
+  exit (EXIT_FAILURE);
+}
+
 bool 
 target_io( const nfc_target_t nt, const byte_t * pbtInput, const size_t szInput, byte_t * pbtOutput, size_t *pszOutput )
 {
@@ -139,6 +150,12 @@ main (int argc, char *argv[])
 {
   const char *acLibnfcVersion;
 
+#ifdef WIN32
+  signal (SIGINT, (void (__cdecl *) (int)) intr_hdlr);
+#else
+  signal (SIGINT, (void (*)()) intr_hdlr);
+#endif
+
   // Try to open the NFC reader
   pnd = nfc_connect (NULL);
 
diff --git a/examples/nfc-emulate-uid.c b/examples/nfc-emulate-uid.c
index 3233558..b1ccca6 100644
--- a/examples/nfc-emulate-uid.c
+++ b/examples/nfc-emulate-uid.c
@@ -37,6 +37,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
+#include <signal.h>
 
 #include <nfc/nfc.h>
 
@@ -54,6 +55,16 @@ byte_t  abtAtqa[2] = { 0x04, 0x00 };
 byte_t  abtUidBcc[5] = { 0xDE, 0xAD, 0xBE, 0xAF, 0x62 };
 byte_t  abtSak[9] = { 0x08, 0xb6, 0xdd };
 
+void
+intr_hdlr (void)
+{
+  printf ("\nQuitting...\n");
+  if (pnd != NULL) {
+    nfc_disconnect(pnd);
+  }
+  exit (EXIT_FAILURE);
+}
+
 void
 print_usage (char *argv[])
 {
@@ -99,6 +110,12 @@ main (int argc, char *argv[])
     }
   }
 
+#ifdef WIN32
+  signal (SIGINT, (void (__cdecl *) (int)) intr_hdlr);
+#else
+  signal (SIGINT, (void (*)()) intr_hdlr);
+#endif
+
   // Try to open the NFC device
   pnd = nfc_connect (NULL);
 
diff --git a/libnfc/drivers/pn53x_usb.c b/libnfc/drivers/pn53x_usb.c
index 94765e2..191417d 100644
--- a/libnfc/drivers/pn53x_usb.c
+++ b/libnfc/drivers/pn53x_usb.c
@@ -45,6 +45,11 @@ Thanks to d18c7db and Okko for example code
 #define BUFFER_LENGTH 256
 #define USB_TIMEOUT   30000
 
+// TODO Move this HACK1 into an upper level in order to benefit to other devices that use PN53x
+static const byte_t ack_frame[] = { 0x00, 0x00, 0xff, 0x00, 0xff, 0x00 };
+
+void pn53x_usb_ack (nfc_device_t * pnd);
+
 // Find transfer endpoints for bulk transfers
 void
 get_end_points (struct usb_device *dev, usb_spec_t * pus)
@@ -195,13 +200,8 @@ pn53x_usb_connect (const nfc_device_desc_t * pndd, const char *target_name, int
         pnd->nds = (nfc_device_spec_t) pus;
         pnd->bActive = true;
 
-        // TODO Move this HACK1 into an upper level in order to benefit to other devices that use PN53x
         // HACK1: Send first an ACK as Abort command, to reset chip before talking to it:
-        uint8_t ack_frame[] = { 0x00, 0x00, 0xff, 0x00, 0xff, 0x00 };
-#ifdef DEBUG
-        PRINT_HEX ("TX", ack_frame, 6);
-#endif
-        usb_bulk_write (pus->pudh, pus->uiEndPointOut, (char *) ack_frame, 6, USB_TIMEOUT);
+        pn53x_usb_ack (pnd);
 
         // HACK2: Then send a GetFirmware command to resync USB toggle bit between host & device
         // in case host used set_configuration and expects the device to have reset its toggle bit, which PN53x doesn't do
@@ -262,6 +262,8 @@ pn53x_usb_disconnect (nfc_device_t * pnd)
   usb_spec_t *pus = (usb_spec_t *) pnd->nds;
   int     ret;
 
+  pn53x_usb_ack (pnd);
+
   if ((ret = usb_release_interface (pus->pudh, 0)) < 0) {
     ERR ("usb_release_interface failed (%i)", ret);
   }
@@ -369,3 +371,13 @@ pn53x_usb_transceive (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szT
 
   return true;
 }
+
+void
+pn53x_usb_ack (nfc_device_t * pnd)
+{
+  usb_spec_t *pus = (usb_spec_t *) pnd->nds;
+#ifdef DEBUG
+  PRINT_HEX ("TX", ack_frame, sizeof (ack_frame));
+#endif
+  usb_bulk_write (pus->pudh, pus->uiEndPointOut, (char *) ack_frame, sizeof (ack_frame), USB_TIMEOUT);
+}