diff --git a/tools/BUILD b/tools/BUILD
index da83877b1..faf310676 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -5,5 +5,7 @@ package(licenses = ["notice"])
 bzl_library(
     name = "defs_bzl",
     srcs = ["defs.bzl"],
-    visibility = ["//visibility:private"],
+    visibility = [
+        "//:sandbox",
+    ],
 )