--- a/SMP/config.h
+++ b/SMP/config.h
@@ -202,7 +202,7 @@
 /* #undef HAVE_NATIVE_mpn_add_n_sub_n */
 #define HAVE_NATIVE_mpn_add_nc 1
 #if defined(__x86_64) || defined(_M_X64)
-#define HAVE_NATIVE_mpn_addaddmul_1msb0 1
+#define HAVE_NATIVE_mpn_addaddmul_1msb0 0
 #define HAVE_NATIVE_mpn_addlsh1_n 1
 #define HAVE_NATIVE_mpn_addlsh2_n 1
 #define HAVE_NATIVE_mpn_addlsh_n 1
-- 
2.8.1.windows.1

