diff --git a/ecg/util.py b/ecg/util.py
index 97dddadb..9ec9185a 100644
--- a/ecg/util.py
+++ b/ecg/util.py
@@ -1,13 +1,13 @@
 import os
-import cPickle as pickle
+import pickle as pickle
 
 def load(dirname):
     preproc_f = os.path.join(dirname, "preproc.bin")
-    with open(preproc_f, 'r') as fid:
+    with open(preproc_f, 'rb') as fid:
         preproc = pickle.load(fid)
     return preproc
 
 def save(preproc, dirname):
     preproc_f = os.path.join(dirname, "preproc.bin")
-    with open(preproc_f, 'w') as fid:
+    with open(preproc_f, 'wb') as fid:
         pickle.dump(preproc, fid)