diff --git a/extlib/benz/boot.c b/extlib/benz/boot.c
index 2c0d06b6..6fb9bff3 100644
--- a/extlib/benz/boot.c
+++ b/extlib/benz/boot.c
@@ -308,13 +308,10 @@ my $src = <<'EOL';
     (let* ((old-bindings
             (current-dynamic-environment))
            (binding
-            (let ((dict (dictionary)))
-              (for-each
-               (lambda (parameter value)
-                 (dictionary-set! dict parameter (list (parameter value #f))))
-               parameters
-               values)
-              dict))
+            (map (lambda (parameter value)
+                   (cons parameter (parameter value #f)))
+                 parameters
+                 values))
            (new-bindings
             (cons binding old-bindings)))
       (dynamic-wind
@@ -709,13 +706,10 @@ const char pic_boot[] =
 "    (let* ((old-bindings\n"
 "            (current-dynamic-environment))\n"
 "           (binding\n"
-"            (let ((dict (dictionary)))\n"
-"              (for-each\n"
-"               (lambda (parameter value)\n"
-"                 (dictionary-set! dict parameter (list (parameter value #f))))\n"
-"               parameters\n"
-"               values)\n"
-"              dict))\n"
+"            (map (lambda (parameter value)\n"
+"                   (cons parameter (parameter value #f)))\n"
+"                 parameters\n"
+"                 values))\n"
 "           (new-bindings\n"
 "            (cons binding old-bindings)))\n"
 "      (dynamic-wind\n"
diff --git a/extlib/benz/var.c b/extlib/benz/var.c
index 84ecda61..7eb4e08a 100644
--- a/extlib/benz/var.c
+++ b/extlib/benz/var.c
@@ -5,13 +5,11 @@
 #include "picrin.h"
 #include "picrin/pair.h"
 #include "picrin/proc.h"
-#include "picrin/dict.h"
 
 static pic_value
 var_lookup(pic_state *pic, pic_value var)
 {
-  pic_value val, env;
-  struct pic_dict *binding;
+  pic_value val, env, binding;
 
   val = pic_ref(pic, pic->PICRIN_BASE, "current-dynamic-environment");
   if (pic_eq_p(val, var)) {
@@ -20,11 +18,13 @@ var_lookup(pic_state *pic, pic_value var)
 
   env = pic_apply0(pic, pic_proc_ptr(val));
   while (! pic_nil_p(env)) {
-    pic_assert_type(pic, pic_car(pic, env), dict);
+    binding = pic_car(pic, env);
 
-    binding = pic_dict_ptr(pic_car(pic, env));
-    if (pic_dict_has(pic, binding, var)) {
-      return pic_dict_ref(pic, binding, var);
+    while (! pic_nil_p(binding)) {
+      if (pic_eq_p(pic_caar(pic, binding), var)) {
+        return pic_car(pic, binding);
+      }
+      binding = pic_cdr(pic, binding);
     }
     env = pic_cdr(pic, env);
   }
@@ -48,7 +48,7 @@ var_call(pic_state *pic)
 
   switch (n) {
   case 0:
-    return pic_car(pic, box);
+    return pic_cdr(pic, box);
 
   case 1:
     conv = pic_attr_ref(pic, pic_obj_value(self), "@@converter");
@@ -57,7 +57,7 @@ var_call(pic_state *pic)
 
       val = pic_apply1(pic, pic_proc_ptr(conv), val);
     }
-    pic_set_car(pic, box, val);
+    pic_set_cdr(pic, box, val);
 
     return pic_none_value();
 
@@ -82,7 +82,7 @@ pic_make_var(pic_state *pic, pic_value init, struct pic_proc *conv)
   struct pic_proc *var;
 
   var = pic_make_proc(pic, var_call, "<var-call>");
-  pic_attr_set(pic, pic_obj_value(var), "@@box", pic_list1(pic, init));
+  pic_attr_set(pic, pic_obj_value(var), "@@box", pic_cons(pic, pic_false_value(), init));
   pic_attr_set(pic, pic_obj_value(var), "@@converter", conv ? pic_obj_value(conv) : pic_false_value());
 
   return var;