diff --git a/libs/gui/BufferItemConsumer.cpp b/libs/gui/BufferItemConsumer.cpp
index 1585aae..4926ceb 100644
--- a/libs/gui/BufferItemConsumer.cpp
+++ b/libs/gui/BufferItemConsumer.cpp
@@ -17,6 +17,7 @@
 //#define LOG_NDEBUG 0
 #define LOG_TAG "BufferItemConsumer"
 //#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+#include <utils/Errors.h>
 #include <utils/Log.h>
 
 #include <inttypes.h>
@@ -132,13 +133,36 @@
     return OK;
 }
 
+status_t BufferItemConsumer::attachBuffer(const sp<GraphicBuffer>& buffer) {
+    if (!buffer) {
+        BI_LOGE("BufferItemConsumer::attachBuffer no input buffer specified.");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock _l(mMutex);
+
+    int slot = INVALID_BUFFER_SLOT;
+    status_t status = mConsumer->attachBuffer(&slot, buffer);
+    if (status != OK) {
+        BI_LOGE("BufferItemConsumer::attachBuffer unable to attach buffer %d", status);
+        return status;
+    }
+
+    mSlots[slot] = {
+            .mGraphicBuffer = buffer,
+            .mFence = nullptr,
+            .mFrameNumber = 0,
+    };
+
+    return OK;
+}
+
 status_t BufferItemConsumer::releaseBuffer(const BufferItem &item,
         const sp<Fence>& releaseFence) {
     Mutex::Autolock _l(mMutex);
     return releaseBufferSlotLocked(item.mSlot, item.mGraphicBuffer, releaseFence);
 }
 
-#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 status_t BufferItemConsumer::releaseBuffer(const sp<GraphicBuffer>& buffer,
                                            const sp<Fence>& releaseFence) {
     Mutex::Autolock _l(mMutex);
@@ -154,7 +178,6 @@
 
     return releaseBufferSlotLocked(slotIndex, buffer, releaseFence);
 }
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 status_t BufferItemConsumer::releaseBufferSlotLocked(int slotIndex, const sp<GraphicBuffer>& buffer,
                                                      const sp<Fence>& releaseFence) {
diff --git a/libs/gui/include/gui/BufferItemConsumer.h b/libs/gui/include/gui/BufferItemConsumer.h
index 0bfa7b2..fc31f46 100644
--- a/libs/gui/include/gui/BufferItemConsumer.h
+++ b/libs/gui/include/gui/BufferItemConsumer.h
@@ -96,6 +96,14 @@
     status_t acquireBuffer(BufferItem* item, nsecs_t presentWhen,
             bool waitForFence = true);
 
+    // Transfer ownership of a buffer to the BufferQueue. On NO_ERROR, the buffer
+    // is considered as if it were acquired. Buffer must not be null.
+    //
+    // Returns
+    //  - BAD_VALUE if buffer is null
+    //  - INVALID_OPERATION if too many buffers have already been acquired
+    status_t attachBuffer(const sp<GraphicBuffer>& buffer);
+
     // Returns an acquired buffer to the queue, allowing it to be reused. Since
     // only a fixed number of buffers may be acquired at a time, old buffers
     // must be released by calling releaseBuffer to ensure new buffers can be
@@ -105,10 +113,8 @@
     status_t releaseBuffer(const BufferItem &item,
             const sp<Fence>& releaseFence = Fence::NO_FENCE);
 
-#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
     status_t releaseBuffer(const sp<GraphicBuffer>& buffer,
                            const sp<Fence>& releaseFence = Fence::NO_FENCE);
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 protected:
 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
diff --git a/libs/gui/tests/BufferItemConsumer_test.cpp b/libs/gui/tests/BufferItemConsumer_test.cpp
index 6b887bf..80eea26 100644
--- a/libs/gui/tests/BufferItemConsumer_test.cpp
+++ b/libs/gui/tests/BufferItemConsumer_test.cpp
@@ -245,6 +245,29 @@
     EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers - 1));
 }
 
+TEST_F(BufferItemConsumerTest, AttachBuffer) {
+    ASSERT_EQ(OK, mBIC->setMaxAcquiredBufferCount(1));
+
+    int slot;
+    DequeueBuffer(&slot);
+    QueueBuffer(slot);
+    AcquireBuffer(&slot);
+
+    sp<GraphicBuffer> newBuffer1 = sp<GraphicBuffer>::make(kWidth, kHeight, kFormat, kUsage);
+    sp<GraphicBuffer> newBuffer2 = sp<GraphicBuffer>::make(kWidth, kHeight, kFormat, kUsage);
+
+    // For some reason, you can attach an extra buffer?
+    // b/400973991 to investigate
+    EXPECT_EQ(OK, mBIC->attachBuffer(newBuffer1));
+    EXPECT_EQ(INVALID_OPERATION, mBIC->attachBuffer(newBuffer2));
+
+    ReleaseBuffer(slot);
+
+    EXPECT_EQ(OK, mBIC->attachBuffer(newBuffer2));
+    EXPECT_EQ(OK, mBIC->releaseBuffer(newBuffer1, Fence::NO_FENCE));
+    EXPECT_EQ(OK, mBIC->releaseBuffer(newBuffer2, Fence::NO_FENCE));
+}
+
 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 // Test that delete BufferItemConsumer triggers onBufferFreed.
 TEST_F(BufferItemConsumerTest, DetachBufferWithBuffer) {