diff --git a/tools/lister.py b/tools/lister.py
index 731413e6c1..3d081649ad 100755
--- a/tools/lister.py
+++ b/tools/lister.py
@@ -1,12 +1,14 @@
 #!/usr/bin/env python
 from __future__ import print_function
 
+from __future__ import absolute_import
 import os
 import sys
 import subprocess
 import re
 from collections import defaultdict
 import argparse
+from six.moves import filter
 
 def get_ftype(fpath, use_shebang):
     ext = os.path.splitext(fpath)[1]