diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index f62373d4ef3..d37bd7bc3ec 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -2221,21 +2221,11 @@ void QRasterPaintEngine::drawImage(const QRectF &r, const QImage &img, const QRe
 
         // Do whatever fillRect() does, but without premultiplying the color if it's already premultiplied.
         QRgb color = img.pixel(sr_l, sr_t);
-        switch (img.format()) {
-        case QImage::Format_ARGB32_Premultiplied:
-        case QImage::Format_ARGB8565_Premultiplied:
-        case QImage::Format_ARGB6666_Premultiplied:
-        case QImage::Format_ARGB8555_Premultiplied:
-        case QImage::Format_ARGB4444_Premultiplied:
-        case QImage::Format_RGBA8888_Premultiplied:
-        case QImage::Format_A2BGR30_Premultiplied:
-        case QImage::Format_A2RGB30_Premultiplied:
+        if (img.pixelFormat().premultiplied() == QPixelFormat::Premultiplied) {
             // Combine premultiplied color with the opacity set on the painter.
             d->solid_color_filler.solidColor = multiplyAlpha256(QRgba64::fromArgb32(color), s->intOpacity);
-            break;
-        default:
+        } else {
             d->solid_color_filler.solidColor = qPremultiply(combineAlpha256(QRgba64::fromArgb32(color), s->intOpacity));
-            break;
         }
 
         if (d->solid_color_filler.solidColor.alphaF() <= 0.0f && s->composition_mode == QPainter::CompositionMode_SourceOver)