diff --git a/root.bp b/root.bp
index 12ca16279..95f089b1a 100644
--- a/root.bp
+++ b/root.bp
@@ -24,6 +24,10 @@ optional_subdirs = [
     "system/core/*",
     "system/extras/*",
     "system/keymaster",
+    "system/hwservicemanager",
+    "system/libhidl",
+    "system/libhwbinder",
     "system/media/*",
     "system/security/*",
+    "system/tools/*",
 ]