diff --git a/ChangeLog b/ChangeLog
index aeb9b9463d..b859561d90 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jun 29 12:41:58 2016  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* test/ruby/test_refinement.rb: skip
+	  test_prepend_after_refine_wb_miss on ARM or MIPS.
+	  [ruby-core:76031] [Bug #12491]
+
 Wed Jun 29 08:45:53 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* proc.c (passed_block): convert passed block symbol to proc.
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index 1984d2c2af..c9de8e83e5 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -785,6 +785,9 @@ class TestRefinement < Test::Unit::TestCase
   eval PrependAfterRefine_CODE
 
   def test_prepend_after_refine_wb_miss
+    if /\A(arm|mips)/ =~ RUBY_PLATFORM
+      skip "too slow cpu"
+    end
     assert_normal_exit %Q{
       GC.stress = true
       10.times{