diff --git a/doc/chibi.scrbl b/doc/chibi.scrbl
index e481d499..1bf94890 100755
--- a/doc/chibi.scrbl
+++ b/doc/chibi.scrbl
@@ -373,6 +373,7 @@ void dostuff(sexp ctx) {
 
 int main(int argc, char** argv) {
   sexp ctx;
+  sexp_init();
   ctx = sexp_make_eval_context(NULL, NULL, NULL, 0, 0);
   sexp_load_standard_env(ctx, NULL, SEXP_SEVEN);
   sexp_load_standard_ports(ctx, NULL, stdin, stdout, stderr, 1);