diff --git a/ChangeLog b/ChangeLog
index 98eb284ffe..421890caa0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 22 21:10:39 2009  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* class.c (rb_obj_basic_to_s_p): typo.  Please become familiar with
+	  the ANSI style. 
+
 Thu Oct 22 20:20:27 2009  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/envutil.rb (assert_in_out_err): test_stdout and
diff --git a/class.c b/class.c
index 0f4394d97d..f8407ca77b 100644
--- a/class.c
+++ b/class.c
@@ -1258,7 +1258,7 @@ rb_define_attr(VALUE klass, const char *name, int read, int write)
 }
 
 int
-rb_obj_basic_to_s_p(obj)
+rb_obj_basic_to_s_p(VALUE obj)
 {
     const rb_method_entry_t *me = rb_method_entry(CLASS_OF(obj), rb_intern("to_s"));
     if (me && me->def && me->def->type == VM_METHOD_TYPE_CFUNC &&