diff --git a/requirements.txt b/requirements.txt
index 3f15762885..555b240d51 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,4 @@
 # process, which may cause wedges in the gate later.
 pbr>=1.8 # Apache-2.0
 Jinja2>=2.8 # BSD License (3 clause)
+six>=1.9.0 # MIT
diff --git a/test-requirements.txt b/test-requirements.txt
index 6489b16c7e..faf4893f80 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,3 +2,5 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 PyYAML>=3.10.0 # MIT
+Jinja2>=2.8 # BSD License (3 clause)
+six>=1.9.0 # MIT
diff --git a/tools/process-templates.py b/tools/process-templates.py
index a15b00e2e0..9a06812b60 100755
--- a/tools/process-templates.py
+++ b/tools/process-templates.py
@@ -14,6 +14,7 @@
 import argparse
 import jinja2
 import os
+import six
 import sys
 import yaml