diff --git a/notebook/services/contents/largefilemanager.py b/notebook/services/contents/largefilemanager.py
index 8f0a8d9b1..10808ba83 100644
--- a/notebook/services/contents/largefilemanager.py
+++ b/notebook/services/contents/largefilemanager.py
@@ -57,7 +57,7 @@ class LargeFileManager(FileContentsManager):
                 bcontent = content.encode('utf8')
             else:
                 b64_bytes = content.encode('ascii')
-                bcontent = base64.decodebytes(b64_bytes)
+                bcontent = base64.b64decode(b64_bytes)
         except Exception as e:
             raise web.HTTPError(
                 400, u'Encoding error saving %s: %s' % (os_path, e)