--- ./coregrind/vg_preloaded.c.orig
+++ ./coregrind/vg_preloaded.c
@@ -42,6 +42,7 @@
    originates from Valgrind.
    ------------------------------------------------------------------ */
 
+#include <features.h>
 #include "pub_core_basics.h"
 #include "pub_core_clreq.h"
 #include "pub_core_debuginfo.h"  // Needed for pub_core_redir.h