diff --git a/pymc3/distributions/continuous.py b/pymc3/distributions/continuous.py
index 7dbc366943..b2a4fa95f9 100644
--- a/pymc3/distributions/continuous.py
+++ b/pymc3/distributions/continuous.py
@@ -284,6 +284,7 @@ def __init__(self, mu=0, sd=None, tau=None, **kwargs):
         assert_negative_support(tau, 'tau', 'Normal')
 
         super(Normal, self).__init__(**kwargs)
+        self.shape = np.broadcast(mu, sd).shape
 
     def random(self, point=None, size=None, repeat=None):
         mu, tau, _ = draw_values([self.mu, self.tau, self.sd],