diff --git a/eddymotion/model.py b/eddymotion/model.py
index ef930206..9ce83233 100644
--- a/eddymotion/model.py
+++ b/eddymotion/model.py
@@ -90,6 +90,7 @@ def predict(self, gradient, **kwargs):
         """Return the *b=0* map."""
         return self._S0
 
+
 class AverageDWModel:
     """A trivial model that returns an average map."""
 
@@ -101,12 +102,13 @@ def __init__(self, gtab, **kwargs):
 
     def fit(self, data, **kwargs):
         """Calculate the average."""
-        self._data =  data.mean(-1)
+        self._data = data.mean(-1)
 
     def predict(self, gradient, **kwargs):
         """Return the average map."""
         return self._data
 
+
 class DTIModel:
     """A wrapper of :obj:`dipy.reconst.dti.TensorModel."""