diff --git a/crypto/compat/posix_win.c b/crypto/compat/posix_win.c
index f8a46ab..0dcc046 100644
--- a/crypto/compat/posix_win.c
+++ b/crypto/compat/posix_win.c
@@ -189,4 +189,11 @@ int gettimeofday(struct timeval * tp, struct timezone * tzp)
 	tp->tv_usec = (long)(system_time.wMilliseconds * 1000);
 	return 0;
 }
+
+unsigned int sleep(unsigned int seconds)
+{
+	Sleep(seconds * 1000);
+	return seconds;
+}
+
 #endif
diff --git a/include/compat/unistd.h b/include/compat/unistd.h
index 4676dc8..5dc2908 100644
--- a/include/compat/unistd.h
+++ b/include/compat/unistd.h
@@ -21,11 +21,7 @@
 
 #define access _access
 
-static inline unsigned int sleep(unsigned int seconds)
-{
-	Sleep(seconds * 1000);
-	return seconds;
-}
+unsigned int sleep(unsigned int seconds);
 
 #endif