diff --git a/GPy/kern/kernpart.py b/GPy/kern/kernpart.py
index 5a852aca..d06749b8 100644
--- a/GPy/kern/kernpart.py
+++ b/GPy/kern/kernpart.py
@@ -9,11 +9,12 @@ class kernpart(object):
 
         :param D: the number of input dimensions to the function
         :type D: int
+
+        Do not instantiate.
         """
         self.D = D
-        self.Nparam = 1.
-        self.name = 'white'
-        self.set_param(np.array([variance]).flatten())
+        self.Nparam = 1
+        self.name = 'unnamed'
 
     def get_param(self):
         raise NotImplementedError
@@ -25,31 +26,31 @@ class kernpart(object):
         raise NotImplementedError
     def Kdiag(self,X,target):
         raise NotImplementedError
-    def dK_dtheta(self,X,X2,target):
+    def dK_dtheta(self,partial,X,X2,target):
         raise NotImplementedError
-    def dKdiag_dtheta(self,X,target):
+    def dKdiag_dtheta(self,partial,X,target):
         raise NotImplementedError
     def psi0(self,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi0_dtheta(self,Z,mu,S,target):
+    def dpsi0_dtheta(self,partial,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi0_dmuS(self,Z,mu,S,target_mu,target_S):
+    def dpsi0_dmuS(self,partial,Z,mu,S,target_mu,target_S):
         raise NotImplementedError
     def psi1(self,Z,mu,S,target):
         raise NotImplementedError
     def dpsi1_dtheta(self,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi1_dZ(self,Z,mu,S,target):
+    def dpsi1_dZ(self,partial,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi1_dmuS(self,Z,mu,S,target_mu,target_S):
+    def dpsi1_dmuS(self,partial,Z,mu,S,target_mu,target_S):
         raise NotImplementedError
     def psi2(self,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi2_dZ(self,Z,mu,S,target):
+    def dpsi2_dZ(self,partial,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi2_dtheta(self,Z,mu,S,target):
+    def dpsi2_dtheta(self,partial,Z,mu,S,target):
         raise NotImplementedError
-    def dpsi2_dmuS(self,Z,mu,S,target_mu,target_S):
+    def dpsi2_dmuS(self,partial,Z,mu,S,target_mu,target_S):
         raise NotImplementedError
     def dK_dX(self,X,X2,target):
         raise NotImplementedError