diff --git a/GPy/core/parameterization/parameter_core.py b/GPy/core/parameterization/parameter_core.py
index 9741b4ef..275198b2 100644
--- a/GPy/core/parameterization/parameter_core.py
+++ b/GPy/core/parameterization/parameter_core.py
@@ -228,10 +228,9 @@ class Constrainable(Nameable, Indexable, Parameterizable):
     
     def log_prior(self):
         """evaluate the prior"""
-        import numpy as np
         if self.priors.size > 0:
             x = self._get_params()
-            return np.sum([p.lnpdf(x[ind]) for p, ind in self.priors.iteritems()])
+            return reduce(lambda a,b: a+b, [p.lnpdf(x[ind]).sum() for p, ind in self.priors.iteritems()], 0)
         return 0.
     
     def _log_prior_gradients(self):
diff --git a/GPy/core/parameterization/priors.py b/GPy/core/parameterization/priors.py
index 3155be64..906fe003 100644
--- a/GPy/core/parameterization/priors.py
+++ b/GPy/core/parameterization/priors.py
@@ -21,6 +21,8 @@ class Prior(object):
         from ...plotting.matplot_dep import priors_plots
         priors_plots.univariate_plot(self)
 
+    def __repr__(self, *args, **kwargs):
+        return self.__str__()
 
 class Gaussian(Prior):
     """