diff --git a/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp b/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
index 49f9fe1..6505440 100644
--- a/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
+++ b/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
@@ -1494,7 +1494,7 @@
         ADD_FAILURE();
     }
 
-    std::lock_guard<std::mutex> l(mLock);
+    std::unique_lock<std::mutex> l(mLock);
     for (const auto& buf : buffers) {
         bool found = false;
         for (size_t idx = 0; idx < mOutstandingBufferIds.size(); idx++) {
@@ -1514,6 +1514,10 @@
         ALOGE("%s: unknown buffer ID %" PRIu64, __FUNCTION__, buf.bufferId);
         ADD_FAILURE();
     }
+    if (!hasOutstandingBuffersLocked()) {
+        l.unlock();
+        mFlushedCondition.notify_one();
+    }
     return Void();
 }