diff --git a/GPy/core/model.py b/GPy/core/model.py
index 28bb4ff5..f70125fd 100644
--- a/GPy/core/model.py
+++ b/GPy/core/model.py
@@ -264,8 +264,11 @@ class model(parameterised):
         return - LL_gradients - prior_gradients
 
     def objective_and_gradients(self, x):
-        obj_f = self.objective_function(x)
-        obj_grads = self.objective_function_gradients(x)
+        self._set_params_transformed(x)
+        obj_f =  -self.log_likelihood() - self.log_prior()
+        LL_gradients = self._transform_gradients(self._log_likelihood_gradients())
+        prior_gradients = self._transform_gradients(self._log_prior_gradients())
+        obj_grads = - LL_gradients - prior_gradients
         return obj_f, obj_grads
 
     def optimize(self, optimizer=None, start=None, **kwargs):