Silence warning if MAX/MIN is already defined
diff --git a/miner.h b/miner.h
index bd80883..73da6b6 100644
--- a/miner.h
+++ b/miner.h
@@ -223,8 +223,12 @@ static inline int fsync (int fd)
#define semtimedop(SEM, SOPS, VAL, TIMEOUT) semop(SEM, SOPS, VAL)
#endif
+#ifndef MIN
#define MIN(x, y) ((x) > (y) ? (y) : (x))
+#endif
+#ifndef MAX
#define MAX(x, y) ((x) > (y) ? (x) : (y))
+#endif
/* Put avalon last to make it the last device it tries to detect to prevent it
* trying to claim same chip but different devices. Adding a device here will