diff --git a/tools/build_rules/verifier_test/BUILD b/tools/build_rules/verifier_test/BUILD
index 49477fd..695520a 100644
--- a/tools/build_rules/verifier_test/BUILD
+++ b/tools/build_rules/verifier_test/BUILD
@@ -5,4 +5,5 @@
 py_binary(
     name = "unbundle",
     srcs = ["unbundle.py"],
+    python_version = "PY2",
 )