diff --git a/scripts/gen_build_prop.py b/scripts/gen_build_prop.py
index 42e3207..799e00b 100644
--- a/scripts/gen_build_prop.py
+++ b/scripts/gen_build_prop.py
@@ -19,9 +19,12 @@
 import argparse
 import contextlib
 import json
+import os
 import subprocess
 import sys
 
+TEST_KEY_DIR = "build/make/target/product/security"
+
 def get_build_variant(product_config):
   if product_config["Eng"]:
     return "eng"