diff --git a/client/sleep.c b/client/sleep.c
index fe397da93..6b0717c6b 100644
--- a/client/sleep.c
+++ b/client/sleep.c
@@ -8,7 +8,7 @@
 // platform-independant sleep macros
 //-----------------------------------------------------------------------------
 
-#ifndef _WIN32
+#ifndef __WIN32
 
 #define _POSIX_C_SOURCE	199309L
 #include "sleep.h"
@@ -24,5 +24,4 @@ void nsleep(uint64_t n) {
   while (nanosleep(&timeout, &timeout) && errno == EINTR);
 }
 
-#endif // _WIN32
-
+#endif // _WIN32
\ No newline at end of file