diff --git a/GPy/core/svgp.py b/GPy/core/svgp.py
index 284386b3..06a9749c 100644
--- a/GPy/core/svgp.py
+++ b/GPy/core/svgp.py
@@ -56,8 +56,7 @@ class SVGP(SparseGP):
         self.kern.update_gradients_full(self.grad_dict['dL_dKmn'], self.Z, self.X)
         grad += self.kern.gradient.copy()
         self.kern.update_gradients_diag(self.grad_dict['dL_dKdiag'], self.X)
-        grad += self.kern.gradient.copy()
-        self.kern.gradient = grad
+        self.kern.gradient += grad
         if not self.Z.is_fixed:# only compute these expensive gradients if we need them
             self.Z.gradient = self.kern.gradients_X(self.grad_dict['dL_dKmm'], self.Z) + self.kern.gradients_X(self.grad_dict['dL_dKmn'], self.Z, self.X)