diff --git a/GPy/testing/rv_transformation_tests.py b/GPy/testing/rv_transformation_tests.py
index f645ca10..0277687a 100644
--- a/GPy/testing/rv_transformation_tests.py
+++ b/GPy/testing/rv_transformation_tests.py
@@ -56,9 +56,9 @@ class RVTransformationTestCase(unittest.TestCase):
         #plt.show(block=True)
         # END OF PLOT
         # Check the gradients at a few random points
+        np.random.seed(12345)
         for i in range(5):
-            m.theta = theta_s[i]
-            m.unset_prior()
+            m.randomize()
             self.assertTrue(m.checkgrad(verbose=True))
 
     def test_Logexp(self):