diff --git a/include/picrin/port.h b/include/picrin/port.h
index b02c173d..0340b3a3 100644
--- a/include/picrin/port.h
+++ b/include/picrin/port.h
@@ -27,4 +27,8 @@ struct pic_port {
 
 pic_value pic_eof_object();
 
+struct pic_port *pic_stdin(pic_state *);
+struct pic_port *pic_stdout(pic_state *);
+struct pic_port *pic_stderr(pic_state *);
+
 #endif
diff --git a/src/port.c b/src/port.c
index 4a73d3ad..cfe6b1bc 100644
--- a/src/port.c
+++ b/src/port.c
@@ -17,6 +17,16 @@ pic_eof_object()
   return v;
 }
 
+struct pic_port *
+pic_stdin(pic_state *pic)
+{
+  struct pic_proc *proc;
+
+  proc = pic_proc_ptr(pic_ref(pic, "current-input-port"));
+
+  return pic_port_ptr(pic_apply(pic, proc, pic_nil_value()));
+}
+
 static void write_pair(pic_state *pic, struct pic_pair *pair);
 static void write_str(pic_state *pic, struct pic_string *str);