diff --git a/src/plugins/platforms/wayland/qwaylandwindow.cpp b/src/plugins/platforms/wayland/qwaylandwindow.cpp
index 1e40998a60f..b7f3c4c7ef7 100644
--- a/src/plugins/platforms/wayland/qwaylandwindow.cpp
+++ b/src/plugins/platforms/wayland/qwaylandwindow.cpp
@@ -438,6 +438,8 @@ void QWaylandWindow::handleContentOrientationChange(Qt::ScreenOrientation orient
         case Qt::InvertedPortraitOrientation:
             transform = isPortrait ? WL_OUTPUT_TRANSFORM_180 : WL_OUTPUT_TRANSFORM_270;
             break;
+        default:
+            Q_UNREACHABLE();
     }
     set_buffer_transform(transform);
     // set_buffer_transform is double buffered, we need to commit.