diff --git a/include/mes/builtins.h b/include/mes/builtins.h
index fed49aef..9b21b641 100644
--- a/include/mes/builtins.h
+++ b/include/mes/builtins.h
@@ -67,6 +67,7 @@ struct scm *hash (struct scm *x, struct scm *size);
 struct scm *hashq_get_handle_ (struct scm *table, struct scm *key, struct scm *dflt);
 struct scm *hashq_ref_ (struct scm *table, struct scm *key, struct scm *dflt);
 struct scm *hash_ref_ (struct scm *table, struct scm *key, struct scm *dflt);
+struct scm *hashq_set_handle_x (struct scm *table, struct scm *key, struct scm *value);
 struct scm *hashq_set_x (struct scm *table, struct scm *key, struct scm *value);
 struct scm *hash_set_x (struct scm *table, struct scm *key, struct scm *value);
 struct scm *hash_table_printer (struct scm *table);
diff --git a/src/builtins.c b/src/builtins.c
index e50214aa..2010f320 100644
--- a/src/builtins.c
+++ b/src/builtins.c
@@ -177,6 +177,7 @@ mes_builtins (struct scm *a)            /*:((internal)) */
   a = init_builtin (builtin_type, "core:hashq-get-handle", 3, &hashq_get_handle_, a);
   a = init_builtin (builtin_type, "core:hashq-ref", 3, &hashq_ref_, a);
   a = init_builtin (builtin_type, "core:hash-ref", 3, &hash_ref_, a);
+  a = init_builtin (builtin_type, "hashq-set-handle!", 3, &hashq_set_handle_x, a);
   a = init_builtin (builtin_type, "hashq-set!", 3, &hashq_set_x, a);
   a = init_builtin (builtin_type, "hash-set!", 3, &hash_set_x, a);
   a = init_builtin (builtin_type, "hash-table-printer", 1, &hash_table_printer, a);
diff --git a/src/hash.c b/src/hash.c
index 7e9187de..0d6b5e65 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -117,13 +117,24 @@ hash_set_x_ (struct scm *table, unsigned hash, struct scm *key, struct scm *valu
   struct scm *bucket = vector_ref_ (buckets, hash);
   if (bucket->type != TPAIR)
     bucket = cell_nil;
-  bucket = acons (key, value, bucket);
+  struct scm *handle = cons (key, value);
+  bucket = cons (handle, bucket);
   vector_set_x_ (buckets, hash, bucket);
-  return value;
+  return handle;
 }
 
 struct scm *
 hashq_set_x (struct scm *table, struct scm *key, struct scm *value)
+{
+  struct scm *s = struct_ref_ (table, 3);
+  long size = s->value;
+  unsigned hash = hashq_ (key, size);
+  struct scm *handle = hash_set_x_ (table, hash, key, value);
+  return handle->cdr;
+}
+
+struct scm *
+hashq_set_handle_x (struct scm *table, struct scm *key, struct scm *value)
 {
   struct scm *s = struct_ref_ (table, 3);
   long size = s->value;
@@ -137,7 +148,8 @@ hash_set_x (struct scm *table, struct scm *key, struct scm *value)
   struct scm *s = struct_ref_ (table, 3);
   long size = s->value;
   unsigned hash = hash_ (key, size);
-  return hash_set_x_ (table, hash, key, value);
+  struct scm *handle = hash_set_x_ (table, hash, key, value);
+  return handle->cdr;
 }
 
 struct scm *