diff --git a/ChangeLog b/ChangeLog
index 898a62131d..10ea1992cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Apr 14 21:23:29 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* variable.c (rb_autoload_p): search superclasses as same as actual
+	  loading.  fixes [ruby-core:35679]
+
 Thu Apr 14 21:21:06 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/win32.h (frexp, modf): wrongly declared as pure in
diff --git a/test/ruby/test_autoload.rb b/test/ruby/test_autoload.rb
index f1a72fa11a..dd049f047a 100644
--- a/test/ruby/test_autoload.rb
+++ b/test/ruby/test_autoload.rb
@@ -34,4 +34,22 @@ p Foo::Bar
     File.unlink(*tmpfiles) rescue nil if tmpfiles
     tmpdirs.each {|dir| Dir.rmdir(dir)}
   end
+
+  def test_autoload_p
+    bug4565 = '[ruby-core:35679]'
+
+    require 'tmpdir'
+    tmpdir = Dir.mktmpdir('autoload')
+    tmpfile = tmpdir + '/foo.rb'
+    a = Module.new do
+      autoload :X, tmpfile
+    end
+    b = Module.new do
+      include a
+    end
+    assert_equal(true, a.const_defined?(:X))
+    assert_equal(true, b.const_defined?(:X))
+    assert_equal(tmpfile, a.autoload?(:X), bug4565)
+    assert_equal(tmpfile, b.autoload?(:X), bug4565)
+  end
 end
diff --git a/variable.c b/variable.c
index 7f813ad6d4..3c9fe7175e 100644
--- a/variable.c
+++ b/variable.c
@@ -1569,7 +1569,10 @@ rb_autoload_p(VALUE mod, ID id)
     NODE *load;
     const char *loading = 0;
 
-    if (!autoload_node_id(mod, id)) return Qnil;
+    while (!autoload_node_id(mod, id)) {
+	mod = RCLASS_SUPER(mod);
+	if (!mod) return Qnil;
+    }
     load = autoload_node(mod, id, &loading);
     if (!load) return Qnil;
     return load && (file = load->nd_lit) ? file : Qnil;