diff --git a/sexp.c b/sexp.c
index a7c9f078..f6b58d02 100644
--- a/sexp.c
+++ b/sexp.c
@@ -1930,7 +1930,10 @@ sexp sexp_write_one (sexp ctx, sexp obj, sexp out) {
         } else {
 #endif
           sexp_write_string(ctx, "#<", out);
-          sexp_write(ctx, sexp_type_name(x), out);
+          if (sexp_stringp(sexp_type_name(x)))
+            sexp_write_string(ctx, sexp_string_data(sexp_type_name(x)), out);
+          else
+            sexp_write(ctx, sexp_type_name(x), out);
           sexp_write_char(ctx, '>', out);
 #if SEXP_USE_TYPE_PRINTERS
         }