diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index f0a05e86..08637904 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -274,7 +274,6 @@ int pic_str_hash(pic_state *, struct pic_string *);
 #include "picrin/state.h"
 
 #include "picrin/cont.h"
-#include "picrin/macro.h"
 
 void *pic_default_allocf(void *, void *, size_t);
 
@@ -294,14 +293,20 @@ void pic_close_port(pic_state *, struct pic_port *port);
     pic_leave(pic, ai);              \
   } while (0)
 
+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 *);
+
 pic_value pic_read(pic_state *, struct pic_port *);
 pic_value pic_read_cstr(pic_state *, const char *);
 
-void pic_load(pic_state *, struct pic_port *);
-void pic_load_cstr(pic_state *, const char *);
+pic_value pic_expand(pic_state *, pic_value, struct pic_env *);
 
 pic_value pic_eval(pic_state *, pic_value, const char *);
 
+void pic_load(pic_state *, struct pic_port *);
+void pic_load_cstr(pic_state *, const char *);
+
 struct pic_proc *pic_make_var(pic_state *, pic_value, struct pic_proc *);
 
 bool pic_data_type_p(pic_state *, pic_value, const pic_data_type *);
diff --git a/extlib/benz/include/picrin/macro.h b/extlib/benz/include/picrin/macro.h
deleted file mode 100644
index 3c2703b8..00000000
--- a/extlib/benz/include/picrin/macro.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_MACRO_H
-#define PICRIN_MACRO_H
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-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))
-
-struct pic_env *pic_make_topenv(pic_state *, struct pic_string *);
-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 *);
-
-pic_value pic_expand(pic_state *, pic_value, struct pic_env *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/extlib/benz/include/picrin/object.h b/extlib/benz/include/picrin/object.h
index c4762df4..0a3310bd 100644
--- a/extlib/benz/include/picrin/object.h
+++ b/extlib/benz/include/picrin/object.h
@@ -203,6 +203,23 @@ struct pic_port {
 #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))
+
+struct pic_env *pic_make_env(pic_state *, struct pic_env *);
+
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/extlib/benz/lib.c b/extlib/benz/lib.c
index c5b4dd28..bf7a7246 100644
--- a/extlib/benz/lib.c
+++ b/extlib/benz/lib.c
@@ -36,7 +36,10 @@ make_library_env(pic_state *pic, struct pic_string *name)
 {
   struct pic_env *env;
 
-  env = pic_make_topenv(pic, name);
+  env = (struct pic_env *)pic_obj_alloc(pic, sizeof(struct pic_env), PIC_TYPE_ENV);
+  env->up = NULL;
+  env->lib = name;
+  kh_init(env, &env->map);
 
   /* set up default environment */
   pic_put_identifier(pic, (pic_id *)pic->sDEFINE_LIBRARY, pic->sDEFINE_LIBRARY, env);
diff --git a/extlib/benz/macro.c b/extlib/benz/macro.c
index f8bae3c2..34266ed1 100644
--- a/extlib/benz/macro.c
+++ b/extlib/benz/macro.c
@@ -21,18 +21,6 @@ pic_make_env(pic_state *pic, struct pic_env *up)
   return env;
 }
 
-struct pic_env *
-pic_make_topenv(pic_state *pic, struct pic_string *lib)
-{
-  struct pic_env *env;
-
-  env = (struct pic_env *)pic_obj_alloc(pic, sizeof(struct pic_env), PIC_TYPE_ENV);
-  env->up = NULL;
-  env->lib = lib;
-  kh_init(env, &env->map);
-  return env;
-}
-
 pic_sym *
 pic_add_identifier(pic_state *pic, pic_id *id, struct pic_env *env)
 {