diff --git a/test/matrix/test_matrix.rb b/test/matrix/test_matrix.rb
index 75f41c2..8146edc 100644
--- a/test/matrix/test_matrix.rb
+++ b/test/matrix/test_matrix.rb
@@ -379,6 +379,16 @@ class TestMatrix < Test::Unit::TestCase
     assert_equal((v * d * v_inv).round(5), m)
   end

+  def test_lup
+    m = Matrix[[1, 2], [3, 4]]
+    l, u, p = m.lup
+    assert(l.lower_triangular?)
+    assert(u.upper_triangular?)
+    assert(p.permutation?)
+    assert(l * u == p * m)
+    assert_equal(m.lup.solve([2, 5]), Vector[1, Rational(1,2)])
+  end
+
   def test_row_vectors
     assert_equal([Vector[1,2,3], Vector[4,5,6]], @m1.row_vectors)
   end