diff --git a/util/libreboot-utils/lib/file.c b/util/libreboot-utils/lib/file.c
index b62cb87a..883d4cd4 100644
--- a/util/libreboot-utils/lib/file.c
+++ b/util/libreboot-utils/lib/file.c
@@ -16,10 +16,6 @@ more correct usage example:
 long max = pathconf("/", _PC_PATH_MAX);
  */
 
-#ifndef _XOPEN_SOURCE
-#define _XOPEN_SOURCE 700
-#endif
-
 /* for openat2: */
 #ifdef __linux__
 #if !defined(USE_OPENAT) || \