diff --git a/repo2docker/docker.py b/repo2docker/docker.py
index 858f793f..d3dde576 100644
--- a/repo2docker/docker.py
+++ b/repo2docker/docker.py
@@ -10,6 +10,7 @@ import tarfile
 import tempfile
 from contextlib import contextmanager
 from pathlib import Path
+import docker
 
 from iso8601 import parse_date
 from traitlets import Dict, List, Unicode