diff --git a/libnfc/drivers/pn532_spi.c b/libnfc/drivers/pn532_spi.c
index cef5a38..05cb000 100644
--- a/libnfc/drivers/pn532_spi.c
+++ b/libnfc/drivers/pn532_spi.c
@@ -34,8 +34,6 @@
 #include <stdio.h>
 #include <inttypes.h>
 #include <string.h>
-#include <unistd.h>
-
 #include <nfc/nfc.h>
 
 #include "drivers.h"
@@ -51,6 +49,22 @@
 #define LOG_CATEGORY "libnfc.driver.pn532_spi"
 #define LOG_GROUP    NFC_LOG_GROUP_DRIVER
 
+#ifndef _WIN32
+// Needed by sleep() under Unix
+#  include <unistd.h>
+#  include <time.h>
+#  define msleep(x) do { \
+     struct timespec xsleep; \
+     xsleep.tv_sec = x / 1000; \
+     xsleep.tv_nsec = (x - xsleep.tv_sec * 1000) * 1000 * 1000; \
+     nanosleep(&xsleep, NULL); \
+   } while (0)
+#else
+// Needed by Sleep() under Windows
+#  include <winbase.h>
+#  define msleep Sleep
+#endif
+
 // Internal data structs
 const struct pn53x_io pn532_spi_io;
 struct pn532_spi_data {
@@ -336,7 +350,7 @@ pn532_spi_wait_for_data(nfc_device *pnd, int timeout)
         return NFC_ETIMEOUT;
       }
 
-      usleep(pn532_spi_poll_interval * 1000);
+      msleep(pn532_spi_poll_interval);
     }
   }