diff --git a/ChangeLog b/ChangeLog
index 71aed6e955..60b51def02 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jan 26 14:26:46 2016  Eric Wong  <e@80x24.org>
+
+	* signal.c (sig_list): use fstring for hash key
+	* test/ruby/test_signal.rb (test_signal_list_dedupe_keys): added
+
 Tue Jan 26 13:08:34 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* signal.c (rb_f_kill): should immediately deliver reserved
diff --git a/signal.c b/signal.c
index cac90db69c..492e682660 100644
--- a/signal.c
+++ b/signal.c
@@ -1347,7 +1347,7 @@ sig_list(void)
     const struct signals *sigs;
 
     for (sigs = siglist; sigs->signm; sigs++) {
-	rb_hash_aset(h, rb_str_new2(sigs->signm), INT2FIX(sigs->signo));
+	rb_hash_aset(h, rb_fstring_cstr(sigs->signm), INT2FIX(sigs->signo));
     }
     return h;
 }
diff --git a/test/ruby/test_signal.rb b/test/ruby/test_signal.rb
index 13d52013b0..c48a4ad400 100644
--- a/test/ruby/test_signal.rb
+++ b/test/ruby/test_signal.rb
@@ -301,4 +301,10 @@ EOS
       assert_ruby_status(['-e', 'Process.kill(:CONT, $$)'])
     end
   end if Process.respond_to?(:kill)
+
+  def test_signal_list_dedupe_keys
+    a = Signal.list.keys.map(&:object_id).sort
+    b = Signal.list.keys.map(&:object_id).sort
+    assert_equal a, b
+  end
 end