diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 0c3859e..88893b6 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -2422,6 +2422,101 @@
     std::future_status status = watcherDiedFuture.wait_for(std::chrono::seconds(1));
     EXPECT_EQ(std::future_status::timeout, status);
 }
+
+TEST_F(SurfaceTest, QueueBufferOutput_TracksReplacements) {
+    sp<BufferItemConsumer> consumer = sp<BufferItemConsumer>::make(GRALLOC_USAGE_SW_READ_OFTEN);
+    ASSERT_EQ(OK, consumer->setMaxBufferCount(3));
+    ASSERT_EQ(OK, consumer->setMaxAcquiredBufferCount(1));
+
+    sp<Surface> surface = consumer->getSurface();
+    sp<StubSurfaceListener> listener = sp<StubSurfaceListener>::make();
+
+    // Async mode sets up an extra buffer so the surface can queue it without waiting.
+    ASSERT_EQ(OK, surface->setMaxDequeuedBufferCount(1));
+    ASSERT_EQ(OK, surface->setAsyncMode(true));
+    ASSERT_EQ(OK, surface->connect(NATIVE_WINDOW_API_CPU, listener));
+
+    sp<GraphicBuffer> buffer;
+    sp<Fence> fence;
+    SurfaceQueueBufferOutput output;
+    BufferItem item;
+
+    // We can queue directly, without an output arg.
+    EXPECT_EQ(OK, surface->dequeueBuffer(&buffer, &fence));
+    EXPECT_EQ(OK, surface->queueBuffer(buffer, fence));
+    EXPECT_EQ(OK, consumer->acquireBuffer(&item, 0));
+    EXPECT_EQ(OK, consumer->releaseBuffer(item));
+
+    // We can queue with an output arg, and that we don't expect to see a replacement.
+    EXPECT_EQ(OK, surface->dequeueBuffer(&buffer, &fence));
+    EXPECT_EQ(OK, surface->queueBuffer(buffer, fence, &output));
+    EXPECT_FALSE(output.bufferReplaced);
+
+    // We expect see a replacement when we queue a second buffer in async mode, and the consumer
+    // hasn't acquired the first one yet.
+    EXPECT_EQ(OK, surface->dequeueBuffer(&buffer, &fence));
+    EXPECT_EQ(OK, surface->queueBuffer(buffer, fence, &output));
+    EXPECT_TRUE(output.bufferReplaced);
+}
+
+TEST_F(SurfaceTest, QueueBufferOutput_TracksReplacements_Plural) {
+    sp<BufferItemConsumer> consumer = sp<BufferItemConsumer>::make(GRALLOC_USAGE_SW_READ_OFTEN);
+    ASSERT_EQ(OK, consumer->setMaxBufferCount(4));
+    ASSERT_EQ(OK, consumer->setMaxAcquiredBufferCount(1));
+
+    sp<Surface> surface = consumer->getSurface();
+    consumer->setName(String8("TRPTest"));
+    sp<StubSurfaceListener> listener = sp<StubSurfaceListener>::make();
+
+    // Async mode sets up an extra buffer so the surface can queue it without waiting.
+    ASSERT_EQ(OK, surface->setMaxDequeuedBufferCount(2));
+    ASSERT_EQ(OK, surface->setAsyncMode(true));
+    ASSERT_EQ(OK, surface->connect(NATIVE_WINDOW_API_CPU, listener));
+
+    // dequeueBuffers requires a vector of a certain size:
+    std::vector<Surface::BatchBuffer> buffers(2);
+    std::vector<Surface::BatchQueuedBuffer> queuedBuffers;
+    std::vector<SurfaceQueueBufferOutput> outputs;
+    BufferItem item;
+
+    auto moveBuffersToQueuedBuffers = [&]() {
+        EXPECT_EQ(2u, buffers.size());
+        EXPECT_NE(nullptr, buffers[0].buffer);
+        EXPECT_NE(nullptr, buffers[1].buffer);
+
+        queuedBuffers.clear();
+        for (auto& buffer : buffers) {
+            auto& queuedBuffer = queuedBuffers.emplace_back();
+            queuedBuffer.buffer = buffer.buffer;
+            queuedBuffer.fenceFd = buffer.fenceFd;
+            queuedBuffer.timestamp = NATIVE_WINDOW_TIMESTAMP_AUTO;
+        }
+        buffers = {{}, {}};
+    };
+
+    // We can queue directly, without an output arg.
+    EXPECT_EQ(OK, surface->dequeueBuffers(&buffers));
+    moveBuffersToQueuedBuffers();
+    EXPECT_EQ(OK, surface->queueBuffers(queuedBuffers));
+    EXPECT_EQ(OK, consumer->acquireBuffer(&item, 0));
+    EXPECT_EQ(OK, consumer->releaseBuffer(item));
+
+    // We can queue with an output arg. Only the second one should be replaced.
+    EXPECT_EQ(OK, surface->dequeueBuffers(&buffers));
+    moveBuffersToQueuedBuffers();
+    EXPECT_EQ(OK, surface->queueBuffers(queuedBuffers, &outputs));
+    EXPECT_EQ(2u, outputs.size());
+    EXPECT_FALSE(outputs[0].bufferReplaced);
+    EXPECT_TRUE(outputs[1].bufferReplaced);
+
+    // Since we haven't acquired anything, both queued buffers will replace the original one.
+    EXPECT_EQ(OK, surface->dequeueBuffers(&buffers));
+    moveBuffersToQueuedBuffers();
+    EXPECT_EQ(OK, surface->queueBuffers(queuedBuffers, &outputs));
+    EXPECT_EQ(2u, outputs.size());
+    EXPECT_TRUE(outputs[0].bufferReplaced);
+    EXPECT_TRUE(outputs[1].bufferReplaced);
+}
 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 } // namespace android