diff --git a/spec/ruby/library/matrix/unitary_spec.rb b/spec/ruby/library/matrix/unitary_spec.rb
index 9c2a106ea5..b0c23e0e84 100644
--- a/spec/ruby/library/matrix/unitary_spec.rb
+++ b/spec/ruby/library/matrix/unitary_spec.rb
@@ -5,10 +5,15 @@ describe "Matrix.unitary?" do
   it "returns false for non unitary matrices" do
     Matrix[[0, 1], [1, 2]].unitary?.should == false
     Matrix[[0, Complex(0, 2)], [Complex(0, 2), 0]].unitary?.should == false
-    Matrix[[0, Complex(0, 1)], [Complex(0, -1), 0]].unitary?.should == false
     Matrix[[1, 1, 0], [0, 1, 1], [1, 0, 1]].unitary?.should == false
   end
 
+  ruby_version_is '2.8' do # matrix v0.3.0
+    it "returns false for non unitary matrix" do
+      Matrix[[0, Complex(0, 1)], [Complex(0, -1), 0]].unitary?.should == true
+    end
+  end
+
   it "returns true for unitary matrices" do
     Matrix[[0, Complex(0, 1)], [Complex(0, 1), 0]].unitary?.should == true
   end