diff --git a/client/deprecated-hid-flasher/flasher/sleep.h b/client/deprecated-hid-flasher/flasher/sleep.h
index 62d9f4d16..f3aac0c8f 100644
--- a/client/deprecated-hid-flasher/flasher/sleep.h
+++ b/client/deprecated-hid-flasher/flasher/sleep.h
@@ -1,10 +1,4 @@
 //-----------------------------------------------------------------------------
-// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
-//
-// This code is licensed to you under the terms of the GNU GPL, version 2 or,
-// at your option, any later version. See the LICENSE.txt file for the text of
-// the license.
-//-----------------------------------------------------------------------------
 // platform-independant sleep macros
 //-----------------------------------------------------------------------------
 
@@ -12,13 +6,18 @@
 #define SLEEP_H__
 
 #ifdef _WIN32
-#include <windows.h>
-#define sleep(n) Sleep(1000 * n)
-#define msleep(n) Sleep(n)
+    #include <windows.h>
+    #define msleep(n) Sleep(n)
 #else
-#include <unistd.h>
-#define msleep(n) usleep(1000 * n)
+    #include <time.h>
+    #include <errno.h>
+    static void nsleep(uint64_t n) {
+        struct timespec timeout;
+        timeout.tv_sec = n / 1000000000;
+        timeout.tv_nsec = n % 1000000000;
+        while (nanosleep(&timeout, &timeout) && errno == EINTR);
+    }
+    #define msleep(n) nsleep(1000000 * (uint64_t)n)
 #endif
 
 #endif
-