diff --git a/ChangeLog b/ChangeLog
index d7fbd01289..55a217aeb3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Wed May 13 17:10:37 2015  Masaki Matsushita <glass.saga@gmail.com>
+
+	* enum.c (enum_to_a): revert r50457.
+	  it requires recursion check.
+	  then, it doesn't make performance improvement.
+	  [Bug #11130] [Feature #9118]
+
 Wed May 13 11:13:40 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (parse_gvar): separate message for gvar without
diff --git a/enum.c b/enum.c
index 2516934814..a49e4b0b74 100644
--- a/enum.c
+++ b/enum.c
@@ -515,14 +515,7 @@ enum_flat_map(VALUE obj)
 static VALUE
 enum_to_a(int argc, VALUE *argv, VALUE obj)
 {
-    VALUE ary, size = rb_check_funcall(obj, id_size, 0, 0);
-
-    if (FIXNUM_P(size)) {
-	ary = rb_ary_new_capa(NUM2LONG(size));
-    }
-    else {
-	ary = rb_ary_new();
-    }
+    VALUE ary = rb_ary_new();
 
     rb_block_call(obj, id_each, argc, argv, collect_all, ary);
     OBJ_INFECT(ary, obj);