# Guard _LARGEFILE64_SOURCE define to avoid warning with append-lfs-flags
# https://bugs.gentoo.org/914505
diff --git a/hdparm.c b/hdparm.c
index eb9796b..a3204f9 100644
--- a/hdparm.c
+++ b/hdparm.c
@@ -4,7 +4,9 @@
  */
 #define HDPARM_VERSION "v9.65"
 
+#ifndef _LARGEFILE64_SOURCE
 #define _LARGEFILE64_SOURCE /*for lseek64*/
+#endif
 #define _BSD_SOURCE	/* for strtoll() */
 #include <unistd.h>
 #include <stdlib.h>