diff --git a/extlib/benz/gc.c b/extlib/benz/gc.c
index 88d2df5a..0bbeb84b 100644
--- a/extlib/benz/gc.c
+++ b/extlib/benz/gc.c
@@ -428,6 +428,7 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     struct pic_lib *lib = (struct pic_lib *)obj;
     gc_mark(pic, lib->name);
     gc_mark_object(pic, (struct pic_object *)lib->env);
+    gc_mark_object(pic, (struct pic_object *)lib->exports);
     break;
   }
   case PIC_TT_IREP: {
@@ -640,8 +641,6 @@ gc_finalize_object(pic_state *pic, struct pic_object *obj)
     break;
   }
   case PIC_TT_LIB: {
-    struct pic_lib *lib = (struct pic_lib *)obj;
-    xh_destroy(&lib->exports);
     break;
   }
   case PIC_TT_IREP: {
diff --git a/extlib/benz/include/picrin/lib.h b/extlib/benz/include/picrin/lib.h
index 98ab3ae8..d0611425 100644
--- a/extlib/benz/include/picrin/lib.h
+++ b/extlib/benz/include/picrin/lib.h
@@ -13,7 +13,7 @@ struct pic_lib {
   PIC_OBJECT_HEADER
   pic_value name;
   struct pic_senv *env;
-  xhash exports;
+  struct pic_dict *exports;
 };
 
 #define pic_lib_ptr(o) ((struct pic_lib *)pic_ptr(o))
diff --git a/extlib/benz/lib.c b/extlib/benz/lib.c
index 37cba2bd..6c54d51b 100644
--- a/extlib/benz/lib.c
+++ b/extlib/benz/lib.c
@@ -9,12 +9,14 @@
 #include "picrin/error.h"
 #include "picrin/string.h"
 #include "picrin/proc.h"
+#include "picrin/dict.h"
 
 struct pic_lib *
 pic_open_library(pic_state *pic, pic_value name)
 {
   struct pic_lib *lib;
   struct pic_senv *senv;
+  struct pic_dict *exports;
 
   if ((lib = pic_find_library(pic, name)) != NULL) {
 
@@ -28,11 +30,12 @@ pic_open_library(pic_state *pic, pic_value name)
   }
 
   senv = pic_null_syntactic_environment(pic);
+  exports = pic_make_dict(pic);
 
   lib = (struct pic_lib *)pic_obj_alloc(pic, sizeof(struct pic_lib), PIC_TT_LIB);
-  lib->env = senv;
   lib->name = name;
-  xh_init_int(&lib->exports, sizeof(pic_sym));
+  lib->env = senv;
+  lib->exports = exports;
 
   /* register! */
   pic->libs = pic_acons(pic, name, pic_obj_value(lib), pic->libs);
@@ -116,8 +119,9 @@ import_table(pic_state *pic, pic_value spec, xhash *imports)
   if (! lib) {
     pic_errorf(pic, "library not found: ~a", spec);
   }
-  for (it = xh_begin(&lib->exports); it != NULL; it = xh_next(it)) {
-    xh_put_int(imports, xh_key(it, pic_sym), &xh_val(it, pic_sym));
+  pic_dict_for_each (sym, lib->exports) {
+    id = pic_sym(pic_dict_ref(pic, lib->exports, sym));
+    xh_put_int(imports, sym, &id);
   }
 
  exit:
@@ -176,7 +180,7 @@ export(pic_state *pic, pic_value spec)
   printf("* exporting %s as %s\n", pic_symbol_name(pic, pic_sym(b)), pic_symbol_name(pic, rename));
 #endif
 
-  xh_put_int(&pic->lib->exports, pic_sym(b), &rename);
+  pic_dict_set(pic, pic->lib->exports, pic_sym(b), pic_sym_value(rename));
 
   return;