diff --git a/gstlal/python/dagparts.py b/gstlal/python/dagparts.py
index 3ebfcc65deef9e56559b1f8093b00291c7390056..cc94133e35c9ec8fdaa39111d47b64239af2176b 100644
--- a/gstlal/python/dagparts.py
+++ b/gstlal/python/dagparts.py
@@ -34,6 +34,7 @@ DAG construction tools.
 
 
 import doctest
+import itertools
 import math
 import os
 import sys