diff --git a/extlib/benz/dict.c b/extlib/benz/dict.c
index 656547d1..88c67e4c 100644
--- a/extlib/benz/dict.c
+++ b/extlib/benz/dict.c
@@ -7,21 +7,20 @@
 
 KHASH_DEFINE(dict, pic_sym *, pic_value, kh_ptr_hash_func, kh_ptr_hash_equal)
 
-struct pic_dict *
+pic_value
 pic_make_dict(pic_state *pic)
 {
   struct pic_dict *dict;
 
   dict = (struct pic_dict *)pic_obj_alloc(pic, sizeof(struct pic_dict), PIC_TYPE_DICT);
   kh_init(dict, &dict->hash);
-
-  return dict;
+  return pic_obj_value(dict);
 }
 
 pic_value
-pic_dict_ref(pic_state *pic, struct pic_dict *dict, pic_sym *key)
+pic_dict_ref(pic_state *pic, pic_value dict, pic_sym *key)
 {
-  khash_t(dict) *h = &dict->hash;
+  khash_t(dict) *h = &pic_dict_ptr(pic, dict)->hash;
   khiter_t it;
 
   it = kh_get(dict, h, key);
@@ -32,9 +31,9 @@ pic_dict_ref(pic_state *pic, struct pic_dict *dict, pic_sym *key)
 }
 
 void
-pic_dict_set(pic_state PIC_UNUSED(*pic), struct pic_dict *dict, pic_sym *key, pic_value val)
+pic_dict_set(pic_state *pic, pic_value dict, pic_sym *key, pic_value val)
 {
-  khash_t(dict) *h = &dict->hash;
+  khash_t(dict) *h = &pic_dict_ptr(pic, dict)->hash;
   int ret;
   khiter_t it;
 
@@ -43,21 +42,23 @@ pic_dict_set(pic_state PIC_UNUSED(*pic), struct pic_dict *dict, pic_sym *key, pi
 }
 
 int
-pic_dict_size(pic_state PIC_UNUSED(*pic), struct pic_dict *dict)
+pic_dict_size(pic_state PIC_UNUSED(*pic), pic_value dict)
 {
-  return kh_size(&dict->hash);
+  return kh_size(&pic_dict_ptr(pic, dict)->hash);
 }
 
 bool
-pic_dict_has(pic_state PIC_UNUSED(*pic), struct pic_dict *dict, pic_sym *key)
+pic_dict_has(pic_state *pic, pic_value dict, pic_sym *key)
 {
-  return kh_get(dict, &dict->hash, key) != kh_end(&dict->hash);
+  khash_t(dict) *h = &pic_dict_ptr(pic, dict)->hash;
+
+  return kh_get(dict, h, key) != kh_end(h);
 }
 
 void
-pic_dict_del(pic_state *pic, struct pic_dict *dict, pic_sym *key)
+pic_dict_del(pic_state *pic, pic_value dict, pic_sym *key)
 {
-  khash_t(dict) *h = &dict->hash;
+  khash_t(dict) *h = &pic_dict_ptr(pic, dict)->hash;
   khiter_t it;
 
   it = kh_get(dict, h, key);
@@ -68,9 +69,9 @@ pic_dict_del(pic_state *pic, struct pic_dict *dict, pic_sym *key)
 }
 
 bool
-pic_dict_next(pic_state PIC_UNUSED(*pic), struct pic_dict *dict, int *iter, pic_sym **key, pic_value *val)
+pic_dict_next(pic_state PIC_UNUSED(*pic), pic_value dict, int *iter, pic_sym **key, pic_value *val)
 {
-  khash_t(dict) *h = &dict->hash;
+  khash_t(dict) *h = &pic_dict_ptr(pic, dict)->hash;
   int it = *iter;
 
   for (it = *iter; it != kh_end(h); ++it) {
@@ -87,20 +88,15 @@ pic_dict_next(pic_state PIC_UNUSED(*pic), struct pic_dict *dict, int *iter, pic_
 static pic_value
 pic_dict_make_dictionary(pic_state *pic)
 {
-  struct pic_dict *dict;
-
   pic_get_args(pic, "");
 
-  dict = pic_make_dict(pic);
-
-  return pic_obj_value(dict);
+  return pic_make_dict(pic);
 }
 
 static pic_value
 pic_dict_dictionary(pic_state *pic)
 {
-  struct pic_dict *dict;
-  pic_value *argv;
+  pic_value dict, *argv;
   int argc, i;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -112,7 +108,7 @@ pic_dict_dictionary(pic_state *pic)
     pic_dict_set(pic, dict, pic_sym_ptr(argv[i]), argv[i+1]);
   }
 
-  return pic_obj_value(dict);
+  return dict;
 }
 
 static pic_value
@@ -128,7 +124,7 @@ pic_dict_dictionary_p(pic_state *pic)
 static pic_value
 pic_dict_dictionary_ref(pic_state *pic)
 {
-  struct pic_dict *dict;
+  pic_value dict;
   pic_sym *key;
 
   pic_get_args(pic, "dm", &dict, &key);
@@ -142,7 +138,7 @@ pic_dict_dictionary_ref(pic_state *pic)
 static pic_value
 pic_dict_dictionary_set(pic_state *pic)
 {
-  struct pic_dict *dict;
+  pic_value dict;
   pic_sym *key;
   pic_value val;
 
@@ -162,7 +158,7 @@ pic_dict_dictionary_set(pic_state *pic)
 static pic_value
 pic_dict_dictionary_size(pic_state *pic)
 {
-  struct pic_dict *dict;
+  pic_value dict;
 
   pic_get_args(pic, "d", &dict);
 
@@ -173,21 +169,15 @@ static pic_value
 pic_dict_dictionary_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  struct pic_dict *dict;
-  khiter_t it;
-  khash_t(dict) *kh;
-  pic_value ret = pic_nil_value(pic);
+  pic_value dict, ret = pic_nil_value(pic);
+  pic_sym *key;
+  int it = 0;
 
   pic_get_args(pic, "ld", &proc, &dict);
 
-  kh = &dict->hash;
-
-  for (it = kh_begin(kh); it != kh_end(kh); ++it) {
-    if (kh_exist(kh, it)) {
-      pic_push(pic, pic_call(pic, proc, 1, pic_obj_value(kh_key(kh, it))), ret);
-    }
+  while (pic_dict_next(pic, dict, &it, &key, NULL)) {
+    pic_push(pic, pic_call(pic, proc, 1, pic_obj_value(key)), ret);
   }
-
   return pic_reverse(pic, ret);
 }
 
@@ -195,18 +185,14 @@ static pic_value
 pic_dict_dictionary_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  struct pic_dict *dict;
-  khiter_t it;
-  khash_t(dict) *kh;
+  pic_value dict;
+  pic_sym *key;
+  int it;
 
   pic_get_args(pic, "ld", &proc, &dict);
 
-  kh = &dict->hash;
-
-  for (it = kh_begin(kh); it != kh_end(kh); ++it) {
-    if (kh_exist(kh, it)) {
-      pic_call(pic, proc, 1, pic_obj_value(kh_key(kh, it)));
-    }
+  while (pic_dict_next(pic, dict, &it, &key, NULL)) {
+    pic_call(pic, proc, 1, pic_obj_value(key));
   }
 
   return pic_undef_value(pic);
@@ -215,8 +201,7 @@ pic_dict_dictionary_for_each(pic_state *pic)
 static pic_value
 pic_dict_dictionary_to_alist(pic_state *pic)
 {
-  struct pic_dict *dict;
-  pic_value val, alist = pic_nil_value(pic);
+  pic_value dict, val, alist = pic_nil_value(pic);
   pic_sym *sym;
   int it = 0;
 
@@ -232,8 +217,7 @@ pic_dict_dictionary_to_alist(pic_state *pic)
 static pic_value
 pic_dict_alist_to_dictionary(pic_state *pic)
 {
-  struct pic_dict *dict;
-  pic_value alist, e, it;
+  pic_value dict, alist, e, it;
 
   pic_get_args(pic, "o", &alist);
 
@@ -244,14 +228,13 @@ pic_dict_alist_to_dictionary(pic_state *pic)
     pic_dict_set(pic, dict, pic_sym_ptr(pic_car(pic, e)), pic_cdr(pic, e));
   }
 
-  return pic_obj_value(dict);
+  return dict;
 }
 
 static pic_value
 pic_dict_dictionary_to_plist(pic_state *pic)
 {
-  struct pic_dict *dict;
-  pic_value val, plist = pic_nil_value(pic);
+  pic_value dict, val, plist = pic_nil_value(pic);
   pic_sym *sym;
   int it = 0;
 
@@ -268,8 +251,7 @@ pic_dict_dictionary_to_plist(pic_state *pic)
 static pic_value
 pic_dict_plist_to_dictionary(pic_state *pic)
 {
-  struct pic_dict *dict;
-  pic_value plist, e;
+  pic_value dict, plist, e;
 
   pic_get_args(pic, "o", &plist);
 
@@ -280,7 +262,7 @@ pic_dict_plist_to_dictionary(pic_state *pic)
     pic_dict_set(pic, dict, pic_sym_ptr(pic_cadr(pic, e)), pic_car(pic, e));
   }
 
-  return pic_obj_value(dict);
+  return dict;
 }
 
 void
diff --git a/extlib/benz/gc.c b/extlib/benz/gc.c
index b6958e31..2a7a29a2 100644
--- a/extlib/benz/gc.c
+++ b/extlib/benz/gc.c
@@ -363,7 +363,7 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     pic_value val;
     int it = 0;
 
-    while (pic_dict_next(pic, &obj->u.dict, &it, &sym, &val)) {
+    while (pic_dict_next(pic, pic_obj_value(&obj->u.dict), &it, &sym, &val)) {
       gc_mark_object(pic, (struct pic_object *)sym);
       gc_mark(pic, val);
     }
diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index 94600879..b2421e3b 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -241,13 +241,13 @@ void pic_vec_set(pic_state *, pic_vec *, int, pic_value);
 int pic_vec_len(pic_state *, pic_vec *);
 
 /* dictionary */
-struct pic_dict *pic_make_dict(pic_state *);
-pic_value pic_dict_ref(pic_state *, struct pic_dict *, pic_sym *);
-void pic_dict_set(pic_state *, struct pic_dict *, pic_sym *, pic_value);
-void pic_dict_del(pic_state *, struct pic_dict *, pic_sym *);
-bool pic_dict_has(pic_state *, struct pic_dict *, pic_sym *);
-int pic_dict_size(pic_state *, struct pic_dict *);
-bool pic_dict_next(pic_state *, struct pic_dict *, int *iter, pic_sym **key, pic_value *val);
+pic_value pic_make_dict(pic_state *);
+pic_value pic_dict_ref(pic_state *, pic_value dict, pic_sym *);
+void pic_dict_set(pic_state *, pic_value dict, pic_sym *, pic_value);
+void pic_dict_del(pic_state *, pic_value dict, pic_sym *);
+bool pic_dict_has(pic_state *, pic_value dict, pic_sym *);
+int pic_dict_size(pic_state *, pic_value dict);
+bool pic_dict_next(pic_state *, pic_value dict, int *iter, pic_sym **key, pic_value *val);
 
 /* ephemeron */
 struct pic_weak *pic_make_weak(pic_state *);
diff --git a/extlib/benz/include/picrin/object.h b/extlib/benz/include/picrin/object.h
index 2335cd59..4f5ddfe9 100644
--- a/extlib/benz/include/picrin/object.h
+++ b/extlib/benz/include/picrin/object.h
@@ -9,11 +9,9 @@
 extern "C" {
 #endif
 
-
-struct pic_object *pic_obj_alloc(pic_state *, size_t, int type);
-
-
-/* symbol & identifier */
+KHASH_DECLARE(env, pic_id *, pic_sym *)
+KHASH_DECLARE(dict, pic_sym *, pic_value)
+KHASH_DECLARE(weak, void *, pic_value)
 
 struct pic_id {
   union {
@@ -29,21 +27,12 @@ struct pic_id {
   } u;
 };
 
-#define pic_sym_ptr(v) ((pic_sym *)pic_obj_ptr(v))
-
-#define pic_id_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ID || pic_type(pic, v) == PIC_TYPE_SYMBOL)
-#define pic_id_ptr(v) ((pic_id *)pic_obj_ptr(v))
-
-pic_id *pic_make_identifier(pic_state *, pic_id *, struct pic_env *);
-
-pic_sym *pic_add_identifier(pic_state *, pic_id *, struct pic_env *);
-pic_sym *pic_put_identifier(pic_state *, pic_id *, pic_sym *, struct pic_env *);
-pic_sym *pic_find_identifier(pic_state *, pic_id *, struct pic_env *);
-
-struct pic_string *pic_id_name(pic_state *, pic_id *);
-
-
-/* pair */
+struct pic_env {
+  PIC_OBJECT_HEADER
+  khash_t(env) map;
+  struct pic_env *up;
+  struct pic_string *lib;
+};
 
 struct pic_pair {
   PIC_OBJECT_HEADER
@@ -51,69 +40,33 @@ struct pic_pair {
   pic_value cdr;
 };
 
-#define pic_pair_ptr(o) ((struct pic_pair *)pic_obj_ptr(o))
-
-
-/* blob */
-
 struct pic_blob {
   PIC_OBJECT_HEADER
   unsigned char *data;
   int len;
 };
 
-#define pic_blob_ptr(v) ((struct pic_blob *)pic_obj_ptr(v))
-
-/* string */
-
 struct pic_string {
   PIC_OBJECT_HEADER
   struct pic_rope *rope;
 };
 
-void pic_rope_incref(pic_state *, struct pic_rope *);
-void pic_rope_decref(pic_state *, struct pic_rope *);
-
-#define pic_str_ptr(o) ((struct pic_string *)pic_obj_ptr(o))
-
-
-/* vector */
-
-struct pic_vector {
-  PIC_OBJECT_HEADER
-  pic_value *data;
-  int len;
-};
-
-#define pic_vec_ptr(o) ((struct pic_vector *)pic_obj_ptr(o))
-
-
-/* dictionary */
-
-KHASH_DECLARE(dict, pic_sym *, pic_value)
-
 struct pic_dict {
   PIC_OBJECT_HEADER
   khash_t(dict) hash;
 };
 
-#define pic_dict_ptr(v) ((struct pic_dict *)pic_obj_ptr(v))
-
-
-/* weak */
-
-KHASH_DECLARE(weak, void *, pic_value)
-
 struct pic_weak {
   PIC_OBJECT_HEADER
   khash_t(weak) hash;
   struct pic_weak *prev;         /* for GC */
 };
 
-#define pic_weak_ptr(v) ((struct pic_weak *)pic_obj_ptr(v))
-
-
-/* data */
+struct pic_vector {
+  PIC_OBJECT_HEADER
+  pic_value *data;
+  int len;
+};
 
 struct pic_data {
   PIC_OBJECT_HEADER
@@ -121,11 +74,6 @@ struct pic_data {
   void *data;
 };
 
-#define pic_data_ptr(o) ((struct pic_data *)pic_obj_ptr(o))
-
-
-/* context */
-
 struct pic_context {
   PIC_OBJECT_HEADER
   pic_value *regs;
@@ -134,11 +82,6 @@ struct pic_context {
   pic_value storage[1];
 };
 
-#define pic_context_ptr(o) ((struct pic_context *)pic_obj_ptr(o))
-
-
-/* procedure */
-
 struct pic_proc {
   PIC_OBJECT_HEADER
   enum {
@@ -158,31 +101,12 @@ struct pic_proc {
   pic_value locals[1];
 };
 
-#define pic_proc_ptr(o) ((struct pic_proc *)pic_obj_ptr(o))
-
-#define pic_proc_func_p(proc) ((proc)->tag == PIC_PROC_TAG_FUNC)
-#define pic_proc_irep_p(proc) ((proc)->tag == PIC_PROC_TAG_IREP)
-
-struct pic_proc *pic_make_proc(pic_state *, pic_func_t, int, pic_value *);
-struct pic_proc *pic_make_proc_irep(pic_state *, struct pic_irep *, struct pic_context *);
-
-
-/* record */
-
 struct pic_record {
   PIC_OBJECT_HEADER
   pic_value type;
   pic_value datum;
 };
 
-#define pic_rec_p(pic, v) (pic_type(pic, v) == PIC_TYPE_RECORD)
-#define pic_rec_ptr(v) ((struct pic_record *)pic_obj_ptr(v))
-
-struct pic_record *pic_make_rec(pic_state *, pic_value, pic_value);
-
-
-/* error */
-
 struct pic_error {
   PIC_OBJECT_HEADER
   pic_sym *type;
@@ -191,38 +115,52 @@ struct pic_error {
   struct pic_string *stack;
 };
 
-#define pic_error_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ERROR)
-#define pic_error_ptr(v) ((struct pic_error *)pic_obj_ptr(v))
-
-struct pic_error *pic_make_error(pic_state *, const char *, const char *, pic_value);
-
-
-/* port */
-
 struct pic_port {
   PIC_OBJECT_HEADER
   xFILE *file;
 };
 
+#define pic_dict_ptr(pic, v) ((struct pic_dict *)pic_obj_ptr(v))
+#define pic_sym_ptr(v) ((pic_sym *)pic_obj_ptr(v))
+#define pic_id_ptr(v) ((pic_id *)pic_obj_ptr(v))
+#define pic_pair_ptr(o) ((struct pic_pair *)pic_obj_ptr(o))
+#define pic_blob_ptr(v) ((struct pic_blob *)pic_obj_ptr(v))
+#define pic_str_ptr(o) ((struct pic_string *)pic_obj_ptr(o))
+#define pic_vec_ptr(o) ((struct pic_vector *)pic_obj_ptr(o))
+#define pic_weak_ptr(v) ((struct pic_weak *)pic_obj_ptr(v))
+#define pic_data_ptr(o) ((struct pic_data *)pic_obj_ptr(o))
+#define pic_context_ptr(o) ((struct pic_context *)pic_obj_ptr(o))
+#define pic_proc_ptr(o) ((struct pic_proc *)pic_obj_ptr(o))
+#define pic_rec_ptr(v) ((struct pic_record *)pic_obj_ptr(v))
+#define pic_error_ptr(v) ((struct pic_error *)pic_obj_ptr(v))
 #define pic_port_ptr(v) ((struct pic_port *)pic_obj_ptr(v))
-
-
-/* environment */
-
-KHASH_DECLARE(env, pic_id *, pic_sym *)
-
-struct pic_env {
-  PIC_OBJECT_HEADER
-  khash_t(env) map;
-  struct pic_env *up;
-  struct pic_string *lib;
-};
-
-#define pic_env_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ENV)
 #define pic_env_ptr(v) ((struct pic_env *)pic_obj_ptr(v))
 
+#define pic_env_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ENV)
+#define pic_error_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ERROR)
+#define pic_rec_p(pic, v) (pic_type(pic, v) == PIC_TYPE_RECORD)
+#define pic_id_p(pic, v) (pic_type(pic, v) == PIC_TYPE_ID || pic_type(pic, v) == PIC_TYPE_SYMBOL)
+
+struct pic_object *pic_obj_alloc(pic_state *, size_t, int type);
+
+pic_id *pic_make_identifier(pic_state *, pic_id *, struct pic_env *);
+struct pic_proc *pic_make_proc(pic_state *, pic_func_t, int, pic_value *);
+struct pic_proc *pic_make_proc_irep(pic_state *, struct pic_irep *, struct pic_context *);
+struct pic_record *pic_make_rec(pic_state *, pic_value, pic_value);
+struct pic_error *pic_make_error(pic_state *, const char *, const char *, pic_value);
 struct pic_env *pic_make_env(pic_state *, struct pic_env *);
 
+pic_sym *pic_add_identifier(pic_state *, pic_id *, struct pic_env *);
+pic_sym *pic_put_identifier(pic_state *, pic_id *, pic_sym *, struct pic_env *);
+pic_sym *pic_find_identifier(pic_state *, pic_id *, struct pic_env *);
+struct pic_string *pic_id_name(pic_state *, pic_id *);
+
+void pic_rope_incref(pic_state *, struct pic_rope *);
+void pic_rope_decref(pic_state *, struct pic_rope *);
+
+#define pic_proc_func_p(proc) ((proc)->tag == PIC_PROC_TAG_FUNC)
+#define pic_proc_irep_p(proc) ((proc)->tag == PIC_PROC_TAG_IREP)
+
 
 #if defined(__cplusplus)
 }
diff --git a/extlib/benz/lib.c b/extlib/benz/lib.c
index bf7a7246..b97c49f0 100644
--- a/extlib/benz/lib.c
+++ b/extlib/benz/lib.c
@@ -57,7 +57,7 @@ pic_make_library(pic_state *pic, const char *lib)
   const char *old_lib;
   struct pic_string *name;
   struct pic_env *env;
-  struct pic_dict *exports;
+  pic_value exports;
   khiter_t it;
   int ret;
 
@@ -76,7 +76,7 @@ pic_make_library(pic_state *pic, const char *lib)
 
   kh_val(h, it).name = name;
   kh_val(h, it).env = env;
-  kh_val(h, it).exports = exports;
+  kh_val(h, it).exports = pic_dict_ptr(pic, exports);
 
   if (pic->lib) {
     pic->lib = get_library(pic, old_lib); /* ltable might be rehashed */
@@ -117,7 +117,7 @@ pic_import(pic_state *pic, const char *lib)
 
   libp = get_library(pic, lib);
 
-  while (pic_dict_next(pic, libp->exports, &it, &name, &val)) {
+  while (pic_dict_next(pic, pic_obj_value(libp->exports), &it, &name, &val)) {
     realname = pic_sym_ptr(val);
 
     if ((uid = pic_find_identifier(pic, (pic_id *)realname, libp->env)) == NULL) {
@@ -130,7 +130,7 @@ pic_import(pic_state *pic, const char *lib)
 void
 pic_export(pic_state *pic, pic_sym *name)
 {
-  pic_dict_set(pic, pic->lib->exports, name, pic_obj_value(name));
+  pic_dict_set(pic, pic_obj_value(pic->lib->exports), name, pic_obj_value(name));
 }
 
 static pic_value
@@ -188,10 +188,10 @@ pic_lib_library_import(pic_state *pic)
 
   libp = get_library(pic, lib);
 
-  if (! pic_dict_has(pic, libp->exports, name)) {
+  if (! pic_dict_has(pic, pic_obj_value(libp->exports), name)) {
     pic_errorf(pic, "attempted to import undefined variable '~s'", pic_obj_value(name));
   } else {
-    realname = pic_sym_ptr(pic_dict_ref(pic, libp->exports, name));
+    realname = pic_sym_ptr(pic_dict_ref(pic, pic_obj_value(libp->exports), name));
   }
 
   if ((uid = pic_find_identifier(pic, (pic_id *)realname, libp->env)) == NULL) {
@@ -214,7 +214,7 @@ pic_lib_library_export(pic_state *pic)
     alias = name;
   }
 
-  pic_dict_set(pic, pic->lib->exports, alias, pic_obj_value(name));
+  pic_dict_set(pic, pic_obj_value(pic->lib->exports), alias, pic_obj_value(name));
 
   return pic_undef_value(pic);
 }
@@ -232,7 +232,7 @@ pic_lib_library_exports(pic_state *pic)
 
   libp = get_library(pic, lib);
 
-  while (pic_dict_next(pic, libp->exports, &it, &sym, NULL)) {
+  while (pic_dict_next(pic, pic_obj_value(libp->exports), &it, &sym, NULL)) {
     pic_push(pic, pic_obj_value(sym), exports);
   }
 
diff --git a/extlib/benz/proc.c b/extlib/benz/proc.c
index 9ce9dc70..b3a8970e 100644
--- a/extlib/benz/proc.c
+++ b/extlib/benz/proc.c
@@ -26,7 +26,7 @@
  *  b   struct pic_blob **      bytevector object
  *  l   struct pic_proc **      lambda object
  *  p   struct pic_port **      port object
- *  d   struct pic_dict **      dictionary object
+ *  d   pic_value *             dictionary object
  *  e   struct pic_error **     error object
  *  r   struct pic_record **    record object
  *
@@ -153,10 +153,13 @@ pic_get_args(pic_state *pic, const char *format, ...)
     PTR_CASE('b', blob, struct pic_blob *)
     PTR_CASE('l', proc, struct pic_proc *)
     PTR_CASE('p', port, struct pic_port *)
-    PTR_CASE('d', dict, struct pic_dict *)
     PTR_CASE('e', error, struct pic_error *)
     PTR_CASE('r', rec, struct pic_record *)
 
+#define OBJ_CASE(c, type) VAL_CASE(c, type, pic_value, v)
+
+    OBJ_CASE('d', dict)
+
     default:
       pic_errorf(pic, "pic_get_args: invalid argument specifier '%c' given", c);
     }
diff --git a/extlib/benz/write.c b/extlib/benz/write.c
index e23bcedc..c80b7fc3 100644
--- a/extlib/benz/write.c
+++ b/extlib/benz/write.c
@@ -238,7 +238,7 @@ write_vec(struct writer_control *p, pic_vec *vec)
 }
 
 static void
-write_dict(struct writer_control *p, struct pic_dict *dict)
+write_dict(struct writer_control *p, pic_value dict)
 {
   pic_state *pic = p->pic;
   xFILE *file = p->file;
@@ -318,7 +318,7 @@ write_core(struct writer_control *p, pic_value obj)
     write_vec(p, pic_vec_ptr(obj));
     break;
   case PIC_TYPE_DICT:
-    write_dict(p, pic_dict_ptr(obj));
+    write_dict(p, obj);
     break;
   default:
     xfprintf(pic, file, "#<%s %p>", pic_typename(pic, pic_type(pic, obj)), pic_obj_ptr(obj));
@@ -369,7 +369,7 @@ traverse(struct writer_control *p, pic_value obj)
         /* dictionary */
         int it = 0;
         pic_value val;
-        while (pic_dict_next(pic, pic_dict_ptr(obj), &it, NULL, &val)) {
+        while (pic_dict_next(pic, obj, &it, NULL, &val)) {
           traverse(p, val);
         }
       }