diff --git a/ChangeLog b/ChangeLog
index 12259e9150..1da985f31e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Oct 16 10:47:43 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* random.c (random_s_rand): ensure default PRNG is re-initialized
+	  after fork.  patched by Eric Wong.  [ruby-core:41209][Bug #5661]
+
 Tue Oct 16 10:21:23 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (rb_f_sub, rb_f_gsub): pass the given block.
diff --git a/random.c b/random.c
index 192110a850..e11b8995f9 100644
--- a/random.c
+++ b/random.c
@@ -1255,6 +1255,7 @@ rb_f_rand(int argc, VALUE *argv, VALUE obj)
 static VALUE
 random_s_rand(int argc, VALUE *argv, VALUE obj)
 {
+    rand_start(&default_rand);
     return random_rand(argc, argv, rb_Random_DEFAULT);
 }
 
diff --git a/test/ruby/test_rand.rb b/test/ruby/test_rand.rb
index 67b6df8562..c7139818de 100644
--- a/test/ruby/test_rand.rb
+++ b/test/ruby/test_rand.rb
@@ -415,14 +415,43 @@ END
 
   def test_fork_shuffle
     pid = fork do
-        (1..10).to_a.shuffle
-        raise 'default seed is not set' if srand == 0
+      (1..10).to_a.shuffle
+      raise 'default seed is not set' if srand == 0
     end
     p2, st = Process.waitpid2(pid)
     assert(st.success?, "#{st.inspect}")
   rescue NotImplementedError, ArgumentError
   end
 
+  def assert_fork_status(n, mesg, &block)
+    IO.pipe do |r, w|
+      (1..n).map do
+        p1 = fork {w.puts(block.call.to_s)}
+        _, st = Process.waitpid2(p1)
+        assert_send([st, :success?], mesg)
+        r.gets.strip
+      end
+    end
+  end
+
+  def test_rand_reseed_on_fork
+    bug5661 = '[ruby-core:41209]'
+
+    assert_fork_status(1, bug5661) {Random.rand(4)}
+    r1, r2 = *assert_fork_status(2, bug5661) {Random.rand}
+    assert_not_equal(r1, r2, bug5661)
+
+    assert_fork_status(1, bug5661) {rand(4)}
+    r1, r2 = *assert_fork_status(2, bug5661) {rand}
+    assert_not_equal(r1, r2, bug5661)
+
+    stable = Random.new
+    assert_fork_status(1, bug5661) {stable.rand(4)}
+    r1, r2 = *assert_fork_status(2, bug5661) {stable.rand}
+    assert_equal(r1, r2, bug5661)
+  rescue NotImplementedError
+  end
+
   def test_seed
     bug3104 = '[ruby-core:29292]'
     rand_1 = Random.new(-1).rand
diff --git a/version.h b/version.h
index 5e4667f611..58e3b12eb7 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.3"
-#define RUBY_PATCHLEVEL 292
+#define RUBY_PATCHLEVEL 293
 
 #define RUBY_RELEASE_DATE "2012-10-16"
 #define RUBY_RELEASE_YEAR 2012