diff --git a/ChangeLog b/ChangeLog
index c8485de275..cf061c5438 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Sep 23 23:57:40 2016  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* vm_method.c (make_method_entry_refined): fix wrong use of ||.
+
 Fri Sep 23 21:38:58 2016  Akinori MUSHA  <knu@iDaemons.org>
 
 	* tool/mdoc2man.rb (Mdoc2Man#parse_macro): Add support for the
diff --git a/vm_method.c b/vm_method.c
index c7417de455..d5780bbe8f 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -447,7 +447,8 @@ make_method_entry_refined(VALUE owner, rb_method_entry_t *me)
 
 	refined.orig_me =
 	    rb_method_entry_alloc(me->called_id, me->owner,
-				  me->defined_class || owner,
+				  me->defined_class ?
+				  me->defined_class : owner,
 				  method_definition_addref(me->def));
 	METHOD_ENTRY_FLAGS_COPY(refined.orig_me, me);
 	refined.owner = owner;