diff --git a/build/docker/ubuntu/Dockerfile b/build/docker/ubuntu/Dockerfile
index 4ad94e1..0b02a70 100644
--- a/build/docker/ubuntu/Dockerfile
+++ b/build/docker/ubuntu/Dockerfile
@@ -37,7 +37,7 @@
 
 # Python dependencies
 RUN apt-get install -y python-all python-all-dev python-all-dbg python-setuptools python-support \
-    python-twisted python-zope.interface
+    python-twisted python-zope.interface python-six
 
 # Ruby dependencies
 RUN apt-get install -y ruby ruby-dev && \