diff --git a/include/chibi/install.h.in b/include/chibi/install.h.in
index a9ca5229..109aa39c 100644
--- a/include/chibi/install.h.in
+++ b/include/chibi/install.h.in
@@ -1,5 +1,6 @@
 #define sexp_so_extension "@CMAKE_SHARED_LIBRARY_SUFFIX@"
 #define sexp_default_module_path "@default_module_path@"
 #define sexp_platform "@platform@"
+#define sexp_architecture "@CMAKE_SYSTEM_PROCESSOR@"
 #define sexp_version "@CMAKE_PROJECT_VERSION@"
 #define sexp_release_name "@release@"
diff --git a/sexp.c b/sexp.c
index 09bbb5ac..6613672e 100644
--- a/sexp.c
+++ b/sexp.c
@@ -460,8 +460,12 @@ sexp sexp_finalize_c_type (sexp ctx, sexp self, sexp_sint_t n, sexp obj) {
 /****************************** contexts ******************************/
 
 static const char* sexp_initial_features[] = {
+#ifdef sexp_architecture
   sexp_architecture,
+#endif
+#ifdef sexp_platform
   sexp_platform,
+#endif
 #if SEXP_BSD
   "bsd",
 #endif