diff --git a/ChangeLog b/ChangeLog
index a735d2e57f..9975706442 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Mar 30 14:35:15 2011  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* vm_insnhelper.h (COPY_CREF): should copy
+	  the NODE_FL_CREF_PUSHED_BY_EVAL flag to hide constants from
+	  methods defined by class_eval.  [ruby-dev:43365]
+
 Wed Mar 30 00:24:53 2011  Tanaka Akira  <akr@fsij.org>
 
 	* ext/stringio/stringio.c: parenthesize macro arguments.
diff --git a/test/ruby/test_defined.rb b/test/ruby/test_defined.rb
index de64ac46f8..bae85c9265 100644
--- a/test/ruby/test_defined.rb
+++ b/test/ruby/test_defined.rb
@@ -86,34 +86,39 @@ class TestDefined < Test::Unit::TestCase
     assert_equal nil, defined?($2)
   end
 
+  class TestAutoloadedSuperclass
+    autoload :A, "a"
+  end
+
+  class TestAutoloadedSubclass < TestAutoloadedSuperclass
+    def a?
+      defined?(A)
+    end
+  end
+
   def test_autoloaded_subclass
     bug = "[ruby-core:35509]"
 
-    klass = Class.new do
-      autoload(:A, "a")
-    end
-    x = klass.new
+    x = TestAutoloadedSuperclass.new
     class << x
       def a?; defined?(A); end
     end
     assert_equal("constant", x.a?, bug)
 
-    klass = Class.new(klass) do
-      def a?; defined?(A); end
+    assert_equal("constant", TestAutoloadedSubclass.new.a?, bug)
+  end
+
+  class TestAutoloadedNoload
+    autoload :A, "a"
+    def a?
+      defined?(A)
     end
-    assert_equal("constant", klass.new.a?, bug)
   end
 
   def test_autoloaded_noload
     loaded = $".dup
     $".clear
-    klass = Class.new do
-      autoload(:A, "a")
-      def a?
-        defined?(A)
-      end
-    end
-    x = klass.new
+    x = TestAutoloadedNoload.new
     assert_equal("constant", x.a?)
     assert_equal([], $")
   ensure
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index ce6e8a66bb..3373594fe3 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -1000,4 +1000,20 @@ class TestModule < Test::Unit::TestCase
     INPUT
     assert_in_out_err([], src, %w(Object :ok), [])
   end
+
+  module A
+    B = 42
+  end
+
+  def test_constant_lookup_in_method_defined_by_class_eval
+    A.class_eval do
+      def self.f
+        B
+      end
+    end
+
+    assert_raise(NameError) do
+      A.f
+    end
+  end
 end
diff --git a/vm_insnhelper.h b/vm_insnhelper.h
index 979c3427bc..31ef216027 100644
--- a/vm_insnhelper.h
+++ b/vm_insnhelper.h
@@ -154,6 +154,9 @@ extern VALUE ruby_vm_const_missing_count;
   (c1)->nd_clss = __tmp_c2->nd_clss; \
   (c1)->nd_visi = __tmp_c2->nd_visi;\
   (c1)->nd_next = __tmp_c2->nd_next; \
+  if (__tmp_c2->flags & NODE_FL_CREF_PUSHED_BY_EVAL) { \
+      (c1)->flags |= NODE_FL_CREF_PUSHED_BY_EVAL; \
+  } \
 } while (0)
 
 #define CALL_METHOD(num, blockptr, flag, id, me, recv) do { \