diff --git a/ChangeLog b/ChangeLog
index 39d885dcea..a13d726ff7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Nov 19 17:48:30 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* object.c (rb_class_superclass): should not raise exception for
+	  BasicObject.  [ruby-Bugs-15668]
+
 Mon Nov 19 16:04:08 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* array.c (rb_ary_permutation): gives all permutations of elements
diff --git a/object.c b/object.c
index edec861a20..0ecb408bae 100644
--- a/object.c
+++ b/object.c
@@ -1410,6 +1410,7 @@ rb_class_superclass(VALUE klass)
     VALUE super = RCLASS_SUPER(klass);
 
     if (!super) {
+	if (klass == rb_cBasicObject) return Qnil;
 	rb_raise(rb_eTypeError, "uninitialized class");
     }
     while (TYPE(super) == T_ICLASS) {