diff --git a/ChangeLog b/ChangeLog
index ad28e34316..92477c2647 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jul 11 23:07:09 2014  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
+
+	* lib/matrix.rb: Fix sign for cross_product [#9499]
+
 Sun Jul  6 23:16:30 2014  Masaya Tarui  <tarui@ruby-lang.org>
 
 	* st.c (st_foreach_check): change start point of search at check
diff --git a/lib/matrix.rb b/lib/matrix.rb
index f82ed65979..b20fd9451f 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1764,9 +1764,9 @@ class Vector
   #
   def cross_product(v)
     Vector.Raise ErrDimensionMismatch unless size == v.size && v.size == 3
-    Vector[ v[1]*@elements[2] - v[2]*@elements[1],
-            v[2]*@elements[0] - v[0]*@elements[2],
-            v[0]*@elements[1] - v[1]*@elements[0] ]
+    Vector[ v[2]*@elements[1] - v[1]*@elements[2],
+            v[0]*@elements[2] - v[2]*@elements[0],
+            v[1]*@elements[0] - v[0]*@elements[1] ]
   end
 
   #
diff --git a/test/matrix/test_vector.rb b/test/matrix/test_vector.rb
index 18660df574..ced774c490 100644
--- a/test/matrix/test_vector.rb
+++ b/test/matrix/test_vector.rb
@@ -146,4 +146,9 @@ class TestVector < Test::Unit::TestCase
     v = Vector[Rational(1,2), 0]
     assert_equal(0.5, v.norm)
   end
+
+  def test_cross_product
+    v = Vector[1, 0, 0].cross_product Vector[0, 1, 0]
+    assert_equal(Vector[0, 0, 1], v)
+  end
 end
diff --git a/version.h b/version.h
index 80c403cb45..701b263b76 100644
--- a/version.h
+++ b/version.h
@@ -1,10 +1,10 @@
 #define RUBY_VERSION "2.1.2"
-#define RUBY_RELEASE_DATE "2014-07-06"
-#define RUBY_PATCHLEVEL 168
+#define RUBY_RELEASE_DATE "2014-07-11"
+#define RUBY_PATCHLEVEL 169
 
 #define RUBY_RELEASE_YEAR 2014
 #define RUBY_RELEASE_MONTH 7
-#define RUBY_RELEASE_DAY 6
+#define RUBY_RELEASE_DAY 11
 
 #include "ruby/version.h"