diff --git a/GPy/kern/src/add.py b/GPy/kern/src/add.py
index ca20e5a9..99fe809b 100644
--- a/GPy/kern/src/add.py
+++ b/GPy/kern/src/add.py
@@ -13,21 +13,15 @@ class Add(CombinationKernel):
     propagates gradients through.
 
     This kernel will take over the active dims of it's subkernels passed in.
-    
-    NOTE: The subkernels will be copies of the original kernels, to prevent 
-    unexpected behavior. 
     """
     def __init__(self, subkerns, name='sum'):
-        _newkerns = []
-        for kern in subkerns:
+        for i, kern in enumerate(subkerns[:]):
             if isinstance(kern, Add):
-                for part in kern.parts:
+                del subkerns[i]
+                for part in kern.parts[::-1]:
                     #kern.unlink_parameter(part)
-                    _newkerns.append(part.copy())
-            else:
-                _newkerns.append(kern.copy())
-                    
-        super(Add, self).__init__(_newkerns, name)
+                    subkerns.insert(i, part.copy())
+        super(Add, self).__init__(subkerns, name)
         self._exact_psicomp = self._check_exact_psicomp()
 
     def _check_exact_psicomp(self):