diff --git a/include/picrin.h b/include/picrin.h
index bbde8010..053f13ec 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -97,6 +97,10 @@ void pic_gc_arena_restore(pic_state *, int);
 pic_state *pic_open(int argc, char *argv[], char **envp);
 void pic_close(pic_state *);
 
+void pic_define(pic_state *, struct pic_lib *, const char *, pic_value); /* symbol is automatically exported */
+pic_value pic_ref(pic_state *, struct pic_lib *, const char *);
+pic_value pic_set(pic_state *, struct pic_lib *, const char *, pic_value);
+
 struct pic_proc *pic_get_proc(pic_state *);
 int pic_get_args(pic_state *, const char *, ...);
 void pic_defun(pic_state *, const char *, pic_func_t);