diff --git a/src/server/kernel/wsurface.cpp b/src/server/kernel/wsurface.cpp
index 4004ed2b7..f1565b584 100644
--- a/src/server/kernel/wsurface.cpp
+++ b/src/server/kernel/wsurface.cpp
@@ -116,20 +116,11 @@ void WSurfacePrivate::updateOutputs()
 
 void WSurfacePrivate::setBuffer(qw_buffer *newBuffer)
 {
-    if (buffer) {
-        if (auto clientBuffer = qw_client_buffer::get(*buffer)) {
-            Q_ASSERT(clientBuffer->handle()->n_ignore_locks > 0);
-            clientBuffer->handle()->n_ignore_locks--;
-        }
-    }
-
     if (newBuffer) {
-        if (auto clientBuffer = qw_client_buffer::get(*newBuffer)) {
-            clientBuffer->handle()->n_ignore_locks++;
-        }
-
-        newBuffer->lock();
-        buffer.reset(newBuffer);
+        auto clientBuffer = qw_client_buffer::get(*newBuffer);
+        auto sourceBuffer = clientBuffer ? qw_buffer::from(clientBuffer->handle()->source) : newBuffer;
+        sourceBuffer->lock();
+        buffer.reset(sourceBuffer);
     } else {
         buffer.reset(nullptr);
     }
diff --git a/src/server/qtquick/wsurfaceitem.cpp b/src/server/qtquick/wsurfaceitem.cpp
index c42711817..dd6bd0fcd 100644
--- a/src/server/qtquick/wsurfaceitem.cpp
+++ b/src/server/qtquick/wsurfaceitem.cpp
@@ -195,6 +195,11 @@ class Q_DECL_HIDDEN WSurfaceItemContentPrivate: public QQuickItemPrivate
 
         Q_ASSERT(!updateTextureConnection);
         updateTextureConnection = surface->safeConnect(&WSurface::bufferChanged, q, [q, this] {
+            // WSurfaceItemContent is for displaying content. When buffer is null, the surface is unmapped.
+            // There is no need for WSurfaceItemContent to reset its buffer to null. It should keep the last
+            // non-null buffer until explicitly destroyed. So we directly return when surface's buffer is null.
+            if (!surface->buffer() && dontCacheLastBuffer)
+                return;
             if (!live) {
                 pendingBuffer.reset(surface->buffer());
                 if (pendingBuffer)