diff --git a/spec/test_payment_spec.rb b/spec/test_payment_spec.rb
index 5e297b6..e9307e6 100644
--- a/spec/test_payment_spec.rb
+++ b/spec/test_payment_spec.rb
@@ -8,4 +8,10 @@
     annuity_given_present(100000000, 0.0144594763, 180).should eq(1563975.1395)
 
   end
-end
\ No newline at end of file
+end
+
+describe "variable payment test" do
+  it "should be the monthly variable payment" do
+    variable_payment(10000000.0,40).should eq(250000)
+  end
+end