diff --git a/ChangeLog b/ChangeLog
index 70e15d14e7..1d546a921b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun 29 14:50:08 2015  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* eval.c (add_activated_refinement): should not include the original
+	  class.
+
 Mon Jun 29 12:09:10 2015  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* README.md: tweak styles. [fix GH-945][ci skip] Patch by @bryndyment
diff --git a/eval.c b/eval.c
index c3c9383a4f..3cc9a2efe9 100644
--- a/eval.c
+++ b/eval.c
@@ -1274,7 +1274,7 @@ add_activated_refinement(VALUE activated_refinements,
     c = iclass = rb_include_class_new(refinement, superclass);
     RCLASS_REFINED_CLASS(c) = klass;
     refinement = RCLASS_SUPER(refinement);
-    while (refinement) {
+    while (refinement && refinement != klass) {
 	FL_SET(refinement, RMODULE_IS_OVERLAID);
 	c = RCLASS_SET_SUPER(c, rb_include_class_new(refinement, RCLASS_SUPER(c)));
 	RCLASS_REFINED_CLASS(c) = klass;