diff --git a/src/gen_context.c b/src/gen_context.c
index 8fab7aa49d..f9176eb996 100644
--- a/src/gen_context.c
+++ b/src/gen_context.c
@@ -13,10 +13,11 @@
 /* We can't require the precomputed tables when creating them. */
 #undef USE_ECMULT_STATIC_PRECOMPUTATION
 
-/* In principle we could use external ASM, but this yields only a minor speedup in
+/* In principle we could use ASM, but this yields only a minor speedup in
    build time and it's very complicated. In particular when cross-compiling, we'd
-   need to build the external ASM for the build and the host machine. */
+   need to build the ASM for the build and the host machine. */
 #undef USE_EXTERNAL_ASM
+#undef USE_ASM_X86_64
 
 #include "../include/secp256k1.h"
 #include "assumptions.h"