diff --git a/horizon/pdp.py b/horizon/pdp.py
index e2e9aae7..b2e282b1 100644
--- a/horizon/pdp.py
+++ b/horizon/pdp.py
@@ -1,4 +1,5 @@
 import logging
+import os
 import sys
 from typing import List
 from uuid import uuid4, UUID