1 files changed, 1 insertions, 1 deletions
diff --git a/unwind.c b/unwind.c
index 80baf6ee..e422cf86 100644
--- a/unwind.c
+++ b/unwind.c
@@ -787,7 +787,7 @@ val uw_register_subtype(val sub, val sup)
   /* Make sub an immediate subtype of sup.
      If sub already registered, we just repoint it. */
   if (sub_entry) {
-    set(cdr_l(sub_entry), sup_entry);
+    rplacd(sub_entry, sup_entry);
   } else {
     sub_entry = cons(sub, sup_entry);
     exception_subtypes = cons(sub_entry, exception_subtypes);