diff --git a/ChangeLog b/ChangeLog
index 797d41314c..c97883b837 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Oct 18 23:37:05 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* marshal.c (r_object0): check inheritance by the internal function.
+	  [ruby-dev:24515]
+
 Mon Oct 18 15:58:01 2004  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* range.c (range_step, range_each): need cast.
diff --git a/marshal.c b/marshal.c
index 71c6d16699..5323fdde25 100644
--- a/marshal.c
+++ b/marshal.c
@@ -1050,7 +1050,7 @@ r_object0(arg, proc, ivp, extmod)
 	      format_error:
 		rb_raise(rb_eArgError, "dump format error (user class)");
 	    }
-	    if (TYPE(v) == T_MODULE || !RTEST(rb_funcall(c, '<', 1, RBASIC(v)->klass))) {
+	    if (TYPE(v) == T_MODULE || !RTEST(rb_class_inherited_p(c, RBASIC(v)->klass))) {
 		VALUE tmp = rb_obj_alloc(c);
 
 		if (TYPE(v) != TYPE(tmp)) goto format_error;