diff --git a/GPy/models/gp_kronecker_gaussian_regression.py b/GPy/models/gp_kronecker_gaussian_regression.py
index 48ce1d97..44177b16 100644
--- a/GPy/models/gp_kronecker_gaussian_regression.py
+++ b/GPy/models/gp_kronecker_gaussian_regression.py
@@ -5,7 +5,6 @@ import numpy as np
 from ..core import Model
 from paramz import ObsAr
 from .. import likelihoods
-from .. import kern
 
 class GPKroneckerGaussianRegression(Model):
     """
@@ -29,14 +28,9 @@ class GPKroneckerGaussianRegression(Model):
     }
 
     """
-    def __init__(self, X1, X2, Y, kern1=None, kern2=None, noise_var=1., name='KGPR'):
+    def __init__(self, X1, X2, Y, kern1, kern2, noise_var=1., name='KGPR'):
         Model.__init__(self, name=name)
 
-        if kern1 is None:
-            kern1 = kern.RBF(X1.shape[1])
-        if kern2 is None:
-            kern2 = kern.RBF(X2.shape[1])
-
         # accept the construction arguments
         self.X1 = ObsAr(X1)
         self.X2 = ObsAr(X2)