diff --git a/ChangeLog b/ChangeLog
index 39aa1afae9..b9ac37804d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri May  8 22:57:24 2015  takiy33  <takiy33@gmail.com>
+
+	* test/matrix/test_matrix.rb (test_determinant): refactor test on
+	  Matrix#determinant, by merging with test_det for an alias method
+	  det.  [Fix GH-897]
+
 Fri May  8 15:43:11 2015  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* lib/net/imap.rb (body_ext_mpart): should work even if body-fld-dsp
diff --git a/test/matrix/test_matrix.rb b/test/matrix/test_matrix.rb
index 7f058abe37..e2530f7366 100644
--- a/test/matrix/test_matrix.rb
+++ b/test/matrix/test_matrix.rb
@@ -179,8 +179,11 @@ class TestMatrix < Test::Unit::TestCase
   end
 
   def test_determinant
+    assert_equal(0, Matrix[[0,0],[0,0]].determinant)
     assert_equal(45, Matrix[[7,6], [3,9]].determinant)
     assert_equal(-18, Matrix[[2,0,1],[0,-2,2],[1,2,3]].determinant)
+    assert_equal(-7, Matrix[[0,0,1],[0,7,6],[1,3,9]].determinant)
+    assert_equal(42, Matrix[[7,0,1,0,12],[8,1,1,9,1],[4,0,0,-7,17],[-1,0,0,-4,8],[10,1,1,8,6]].determinant)
   end
 
   def test_new_matrix
@@ -417,10 +420,7 @@ class TestMatrix < Test::Unit::TestCase
   end
 
   def test_det
-    assert_equal(45, Matrix[[7,6],[3,9]].det)
-    assert_equal(0, Matrix[[0,0],[0,0]].det)
-    assert_equal(-7, Matrix[[0,0,1],[0,7,6],[1,3,9]].det)
-    assert_equal(42, Matrix[[7,0,1,0,12],[8,1,1,9,1],[4,0,0,-7,17],[-1,0,0,-4,8],[10,1,1,8,6]].det)
+    assert_equal(Matrix.instance_method(:determinant), Matrix.instance_method(:det))
   end
 
   def test_rank2