diff --git a/signal.c b/signal.c
index e846f6c2..27b372e3 100644
--- a/signal.c
+++ b/signal.c
@@ -189,7 +189,7 @@ static const struct xlat sigvec_flags[] = {
 
 #ifdef HAVE_SIGACTION
 
-#if defined LINUX && defined I386
+#if defined LINUX && (defined I386 || defined X86_64)
 /* The libc headers do not define this constant since it should only be
    used by the implementation.  So wwe define it here.  */
 # ifndef SA_RESTORER