The x86-64 headers define NSIG to be 32, but it's actually 64

diff --git a/include/arch/x86_64/klibc/archsignal.h b/include/arch/x86_64/klibc/archsignal.h
index 74e82e1..5272414 100644
--- a/include/arch/x86_64/klibc/archsignal.h
+++ b/include/arch/x86_64/klibc/archsignal.h
@@ -8,6 +8,10 @@
 #ifndef _KLIBC_ARCHSIGNAL_H
 #define _KLIBC_ARCHSIGNAL_H
 
-/* No special stuff for this architecture */
+/* The x86-64 headers defines NSIG 32, but it's actually 64 */
+#undef  _NSIG
+#undef  NSIG
+#define _NSIG 64
+#define NSIG  _NSIG
 
 #endif