diff --git a/VoldNativeService.h b/VoldNativeService.h
index e04c259..61f5c3f 100644
--- a/VoldNativeService.h
+++ b/VoldNativeService.h
@@ -123,9 +123,9 @@
                                  const std::string& secret);
     binder::Status lockUserKey(int32_t userId);
 
-    binder::Status prepareUserStorage(const std::unique_ptr<std::string>& uuid, int32_t userId,
+    binder::Status prepareUserStorage(const std::optional<std::string>& uuid, int32_t userId,
                                       int32_t userSerial, int32_t flags);
-    binder::Status destroyUserStorage(const std::unique_ptr<std::string>& uuid, int32_t userId,
+    binder::Status destroyUserStorage(const std::optional<std::string>& uuid, int32_t userId,
                                       int32_t flags);
 
     binder::Status prepareSandboxForApp(const std::string& packageName, int32_t appId,