diff --git a/ChangeLog b/ChangeLog
index e3ece8073f..a9d9aac68b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 22 00:12:33 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* lib/securerandom.rb (SecureRandom::gen_random): use /dev/urandom
+	  for initialize OpenSSL's rand.
+
 Wed Oct 21 12:10:04 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* ext/openssl/ossl_rand.c (ossl_rand_bytes): RAND_bytes could
diff --git a/lib/securerandom.rb b/lib/securerandom.rb
index f53087b954..b08b62b746 100644
--- a/lib/securerandom.rb
+++ b/lib/securerandom.rb
@@ -56,6 +56,10 @@ module SecureRandom
         now = Process.clock_gettime(Process::CLOCK_REALTIME, :nanosecond)
         ary = [now, @pid, pid]
         OpenSSL::Random.random_add(ary.join("").to_s, 0.0)
+        seed = Random.raw_seed(16)
+        if (seed)
+          OpenSSL::Random.random_add(seed, 16)
+        end
         @pid = pid
       end
       return OpenSSL::Random.random_bytes(n)