diff --git a/ChangeLog b/ChangeLog
index 1472f90787..425cb9e8bc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,7 @@
-Thu Mar 24 23:05:42 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Thu Mar 24 23:06:29 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_insnhelper.c (vm_get_ev_const): should not autoload in
+	  defined? mode.
 
 	* variable.c (rb_const_defined_0): fix autoloading base.
 	  [ruby-core:35509]
diff --git a/test/ruby/test_defined.rb b/test/ruby/test_defined.rb
index e1d685275d..6a1f702648 100644
--- a/test/ruby/test_defined.rb
+++ b/test/ruby/test_defined.rb
@@ -103,4 +103,15 @@ class TestDefined < Test::Unit::TestCase
     end
     assert_equal("constant", klass.new.a?, bug)
   end
+
+  def test_autoloaded_noload
+    klass = Class.new do
+      autoload(:A, "a")
+      def a?
+        defined?(A)
+      end
+    end
+    x = klass.new
+    assert_equal("constant", x.a?)
+  end
 end
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 3666aed53e..00a21e3669 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -1177,6 +1177,7 @@ vm_get_ev_const(rb_thread_t *th, const rb_iseq_t *iseq,
 		    if (val == Qundef) {
 			if (am == klass) break;
 			am = klass;
+			if (is_defined) return 1;
 			rb_autoload_load(klass, id);
 			goto search_continue;
 		    }