diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index 73504f87..d0dedfa5 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -201,6 +201,10 @@ void pic_load_port(pic_state *, struct pic_port *);
 void pic_load_cstr(pic_state *, const char *);
 
 pic_value pic_funcall(pic_state *pic, struct pic_lib *, const char *, pic_list);
+pic_value pic_funcall0(pic_state *pic, struct pic_lib *, const char *);
+pic_value pic_funcall1(pic_state *pic, struct pic_lib *, const char *, pic_value);
+pic_value pic_funcall2(pic_state *pic, struct pic_lib *, const char *, pic_value, pic_value);
+pic_value pic_funcall3(pic_state *pic, struct pic_lib *, const char *, pic_value, pic_value, pic_value);
 pic_value pic_ref(pic_state *, struct pic_lib *, const char *);
 void pic_set(pic_state *, struct pic_lib *, const char *, pic_value);
 
diff --git a/extlib/benz/port.c b/extlib/benz/port.c
index 9100be4a..51fc5439 100644
--- a/extlib/benz/port.c
+++ b/extlib/benz/port.c
@@ -14,35 +14,20 @@ pic_eof_object()
   return v;
 }
 
-struct pic_port *
-pic_stdin(pic_state *pic)
-{
-  pic_value obj;
+#define DEFINE_STANDARD_PORT_ACCESSOR(name, var)        \
+  struct pic_port *                                     \
+  name(pic_state *pic)                                  \
+  {                                                     \
+    pic_value obj;                                      \
+                                                        \
+    obj = pic_funcall0(pic, pic->PICRIN_BASE, var);     \
+                                                        \
+    return pic_port_ptr(obj);                           \
+  }
 
-  obj = pic_funcall(pic, pic->PICRIN_BASE, "current-input-port", pic_nil_value());
-
-  return pic_port_ptr(obj);
-}
-
-struct pic_port *
-pic_stdout(pic_state *pic)
-{
-  pic_value obj;
-
-  obj = pic_funcall(pic, pic->PICRIN_BASE, "current-output-port", pic_nil_value());
-
-  return pic_port_ptr(obj);
-}
-
-struct pic_port *
-pic_stderr(pic_state *pic)
-{
-  pic_value obj;
-
-  obj = pic_funcall(pic, pic->PICRIN_BASE, "current-error-port", pic_nil_value());
-
-  return pic_port_ptr(obj);
-}
+DEFINE_STANDARD_PORT_ACCESSOR(pic_stdin, "current-input-port")
+DEFINE_STANDARD_PORT_ACCESSOR(pic_stdout, "current-output-port")
+DEFINE_STANDARD_PORT_ACCESSOR(pic_stderr, "current-error-port")
 
 struct pic_port *
 pic_make_standard_port(pic_state *pic, xFILE *file, short dir)
diff --git a/extlib/benz/vm.c b/extlib/benz/vm.c
index 791529d0..2f56467f 100644
--- a/extlib/benz/vm.c
+++ b/extlib/benz/vm.c
@@ -467,6 +467,12 @@ pic_funcall(pic_state *pic, struct pic_lib *lib, const char *name, pic_list args
   return pic_apply(pic, pic_proc_ptr(proc), args);
 }
 
+pic_value
+pic_funcall0(pic_state *pic, struct pic_lib *lib, const char *name)
+{
+  return pic_funcall(pic, lib, name, pic_nil_value());
+}
+
 void
 pic_defun(pic_state *pic, const char *name, pic_func_t cfunc)
 {