diff --git a/GPy/core/model.py b/GPy/core/model.py
index 5de114c5..452138cc 100644
--- a/GPy/core/model.py
+++ b/GPy/core/model.py
@@ -477,13 +477,15 @@ class Model(Parameterized):
         if not hasattr(self, 'kern'):
             raise ValueError, "this Model has no kernel"
 
-        k = [p for p in self.kern.parts if p.name in ['rbf', 'linear']]
+        k = [p for p in self.kern.parts if p.name in ['rbf', 'linear','rbf_inv']]
         if (not len(k) == 1) or (not k[0].ARD):
             raise ValueError, "cannot determine sensitivity for this kernel"
         k = k[0]
 
         if k.name == 'rbf':
             return k.lengthscale
+        elif k.name == 'rbf_inv':
+            return 1. / k.inv_lengthscale
         elif k.name == 'linear':
             return 1. / k.variances