diff --git a/ChangeLog b/ChangeLog
index 7044869583..c2e7d640ed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Aug  6 16:14:32 2013  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* vm_eval.c (eval_string_with_cref): copy cref to limit the scope of
+	  refienements in the eval string. [ruby-core:56329] [Bug #8722]
+
+	* test/ruby/test_refinement.rb: related test.
+
 Tue Aug  6 12:23:12 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (rb_big_realloc): Use VALGRIND_MAKE_MEM_UNDEFINED to
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index f1f5e9d3e5..ffecebd5e8 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -929,6 +929,38 @@ class TestRefinement < Test::Unit::TestCase
     assert_equal("FooExt2#y Foo#y", FooFoo2ExtClient.invoke_y_on(foo))
   end
 
+  def test_eval_scoping
+    assert_in_out_err([], <<-INPUT, ["HELLO WORLD", "dlrow olleh", "HELLO WORLD"], [])
+      module M
+        refine String do
+          def upcase
+            reverse
+          end
+        end
+      end
+
+      puts "hello world".upcase
+      puts eval(%{using M; "hello world".upcase})
+      puts "hello world".upcase
+    INPUT
+  end
+
+  def test_eval_with_binding_scoping
+    assert_in_out_err([], <<-INPUT, ["HELLO WORLD", "dlrow olleh", "HELLO WORLD"], [])
+      module M
+        refine String do
+          def upcase
+            reverse
+          end
+        end
+      end
+
+      puts "hello world".upcase
+      puts eval(%{using M; "hello world".upcase}, TOPLEVEL_BINDING)
+      puts eval(%{"hello world".upcase}, TOPLEVEL_BINDING)
+    INPUT
+  end
+
   private
 
   def eval_using(mod, s)
diff --git a/vm_eval.c b/vm_eval.c
index ce61849f2c..4493c1c929 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -1186,6 +1186,8 @@ eval_string_with_cref(VALUE self, VALUE src, VALUE scope, NODE *cref, volatile V
     rb_block_t block, *base_block;
     volatile int parse_in_eval;
     volatile int mild_compile_error;
+    NODE *orig_cref;
+    VALUE crefval;
 
     if (file == 0) {
 	file = rb_sourcefilename();
@@ -1243,7 +1245,14 @@ eval_string_with_cref(VALUE self, VALUE src, VALUE scope, NODE *cref, volatile V
 	th->mild_compile_error--;
 	th->parse_in_eval--;
 
+	if (!cref && base_block->iseq) {
+	    orig_cref = rb_vm_get_cref(base_block->iseq, base_block->ep);
+	    cref = NEW_CREF(Qnil);
+	    crefval = (VALUE) cref;
+	    COPY_CREF(cref, orig_cref);
+	}
 	vm_set_eval_stack(th, iseqval, cref, base_block);
+	RB_GC_GUARD(crefval);
 
 	if (0) {		/* for debug */
 	    VALUE disasm = rb_iseq_disasm(iseqval);