1 files changed, 11 insertions, 2 deletions
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 38b3bdadd35..a407cde2a7c 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -1156,9 +1156,13 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
     case QtWindows::MoveEvent:
         platformWindow->handleMoved();
         return true;
-    case QtWindows::ResizeEvent:
+    case QtWindows::ResizeEvent: {
+        QWindow *window = platformWindow->window();
         platformWindow->handleResized(static_cast<int>(wParam), lParam);
+        if (window->flags().testFlags(Qt::ExpandedClientAreaHint))
+            platformWindow->updateCustomTitlebar();
         return true;
+    }
     case QtWindows::QuerySizeHints:
         platformWindow->getSizeHints(reinterpret_cast<MINMAXINFO *>(lParam));
         return true;// maybe available on some SDKs revisit WM_NCCALCSIZE
@@ -1174,8 +1178,12 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
         return platformWindow->handleNonClientActivate(result);
     case QtWindows::GeometryChangingEvent:
         return platformWindow->handleGeometryChanging(&msg);
-    case QtWindows::ExposeEvent:
+    case QtWindows::ExposeEvent: {
+        QWindow *window = platformWindow->window();
+        if (window->flags().testFlags(Qt::ExpandedClientAreaHint))
+            platformWindow->updateCustomTitlebar();
         return platformWindow->handleWmPaint(hwnd, message, wParam, lParam, result);
+    }
     case QtWindows::NonClientMouseEvent:
         if (!platformWindow->frameStrutEventsEnabled())
             break;
@@ -1219,6 +1227,7 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
     case QtWindows::FocusInEvent: // see QWindowsWindow::requestActivateWindow().
         if (platformWindow->window()->flags() & Qt::WindowDoesNotAcceptFocus)
             return false;
+        [[fallthrough]];
     case QtWindows::FocusOutEvent:
         handleFocusEvent(et, platformWindow);
         return true;