diff --git a/ChangeLog b/ChangeLog
index 10bfe629eb..123c8b61c8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jun 16 16:03:59 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* object.c (rb_class_inherited_p): singleton class inherits Class
+	  rather than its object's class.  [ruby-dev:23690]
+
 Wed Jun 16 16:01:17 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* gc.c (stack_grow_direction): memoize the direction.
diff --git a/object.c b/object.c
index 2fb2bd0638..f2c8c5f522 100644
--- a/object.c
+++ b/object.c
@@ -1257,6 +1257,11 @@ rb_class_inherited_p(mod, arg)
 	rb_raise(rb_eTypeError, "compared with non class/module");
     }
 
+    if (FL_TEST(mod, FL_SINGLETON)) {
+	if (RCLASS(mod)->m_tbl == RCLASS(arg)->m_tbl)
+	    return Qtrue;
+	mod = RBASIC(mod)->klass;
+    }
     while (mod) {
 	if (RCLASS(mod)->m_tbl == RCLASS(arg)->m_tbl)
 	    return Qtrue;