diff --git a/src/gui/image/qimage_p.h b/src/gui/image/qimage_p.h
index ca7a4de4d8..7dbddbc67d 100644
--- a/src/gui/image/qimage_p.h
+++ b/src/gui/image/qimage_p.h
@@ -322,6 +322,63 @@ inline QImage::Format qt_alphaVersion(QImage::Format format)
     return QImage::Format_ARGB32_Premultiplied;
 }
 
+// Returns an opaque version that is compatible with format
+inline QImage::Format qt_maybeDataCompatibleOpaqueVersion(QImage::Format format)
+{
+    switch (format) {
+    case QImage::Format_ARGB6666_Premultiplied:
+        return QImage::Format_RGB666;
+    case QImage::Format_ARGB4444_Premultiplied:
+        return QImage::Format_RGB444;
+    case QImage::Format_RGBA8888:
+    case QImage::Format_RGBA8888_Premultiplied:
+        return QImage::Format_RGBX8888;
+    case QImage::Format_A2BGR30_Premultiplied:
+        return QImage::Format_BGR30;
+    case QImage::Format_A2RGB30_Premultiplied:
+        return QImage::Format_RGB30;
+    case QImage::Format_RGBA64:
+    case QImage::Format_RGBA64_Premultiplied:
+        return QImage::Format_RGBX64;
+    case QImage::Format_RGBA16FPx4:
+    case QImage::Format_RGBA16FPx4_Premultiplied:
+        return QImage::Format_RGBX16FPx4;
+    case QImage::Format_RGBA32FPx4:
+    case QImage::Format_RGBA32FPx4_Premultiplied:
+        return QImage::Format_RGBX32FPx4;
+    case QImage::Format_ARGB32_Premultiplied:
+    case QImage::Format_ARGB32:
+        return QImage::Format_RGB32;
+    case QImage::Format_RGB16:
+    case QImage::Format_RGB32:
+    case QImage::Format_RGB444:
+    case QImage::Format_RGB555:
+    case QImage::Format_RGB666:
+    case QImage::Format_RGB888:
+    case QImage::Format_BGR888:
+    case QImage::Format_RGBX8888:
+    case QImage::Format_BGR30:
+    case QImage::Format_RGB30:
+    case QImage::Format_RGBX64:
+    case QImage::Format_RGBX16FPx4:
+    case QImage::Format_RGBX32FPx4:
+    case QImage::Format_Grayscale8:
+    case QImage::Format_Grayscale16:
+    case QImage::Format_CMYK32:
+        return format; // Already opaque
+    case QImage::Format_Mono:
+    case QImage::Format_MonoLSB:
+    case QImage::Format_Indexed8:
+    case QImage::Format_ARGB8565_Premultiplied:
+    case QImage::Format_ARGB8555_Premultiplied:
+    case QImage::Format_Alpha8:
+    case QImage::Format_Invalid:
+    case QImage::NImageFormats:
+        break;
+    }
+    return format; // No compatible opaque versions
+}
+
 constexpr QImage::Format qt_toUnpremultipliedFormat(QImage::Format format)
 {
     // Assumes input is already a premultiplied format with an unpremultiplied counterpart
@@ -380,10 +437,60 @@ inline bool qt_fpColorPrecision(QImage::Format format)
     return false;
 }
 
-inline QImage::Format qt_maybeAlphaVersionWithSameDepth(QImage::Format format)
+inline QImage::Format qt_maybeDataCompatibleAlphaVersion(QImage::Format format)
 {
-    const QImage::Format toFormat = qt_alphaVersion(format);
-    return qt_depthForFormat(format) == qt_depthForFormat(toFormat) ? toFormat : format;
+    switch (format) {
+    case QImage::Format_RGB32:
+        return QImage::Format_ARGB32_Premultiplied;
+    case QImage::Format_RGB666:
+        return QImage::Format_ARGB6666_Premultiplied;
+    case QImage::Format_RGB444:
+        return QImage::Format_ARGB4444_Premultiplied;
+    case QImage::Format_RGBX8888:
+        return QImage::Format_RGBA8888_Premultiplied;
+    case QImage::Format_BGR30:
+        return QImage::Format_A2BGR30_Premultiplied;
+    case QImage::Format_RGB30:
+        return QImage::Format_A2RGB30_Premultiplied;
+    case QImage::Format_RGBX64:
+        return QImage::Format_RGBA64_Premultiplied;
+    case QImage::Format_RGBX16FPx4:
+        return QImage::Format_RGBA16FPx4_Premultiplied;
+    case QImage::Format_RGBX32FPx4:
+        return QImage::Format_RGBA32FPx4_Premultiplied;
+    case QImage::Format_ARGB32:
+    case QImage::Format_ARGB32_Premultiplied:
+    case QImage::Format_ARGB8565_Premultiplied:
+    case QImage::Format_ARGB8555_Premultiplied:
+    case QImage::Format_ARGB6666_Premultiplied:
+    case QImage::Format_ARGB4444_Premultiplied:
+    case QImage::Format_RGBA8888:
+    case QImage::Format_RGBA8888_Premultiplied:
+    case QImage::Format_A2BGR30_Premultiplied:
+    case QImage::Format_A2RGB30_Premultiplied:
+    case QImage::Format_Alpha8:
+    case QImage::Format_RGBA64:
+    case QImage::Format_RGBA64_Premultiplied:
+    case QImage::Format_RGBA16FPx4:
+    case QImage::Format_RGBA16FPx4_Premultiplied:
+    case QImage::Format_RGBA32FPx4:
+    case QImage::Format_RGBA32FPx4_Premultiplied:
+        return format; // Already alpha versions
+    case QImage::Format_Mono:
+    case QImage::Format_MonoLSB:
+    case QImage::Format_Indexed8:
+    case QImage::Format_RGB16:
+    case QImage::Format_RGB555:
+    case QImage::Format_RGB888:
+    case QImage::Format_BGR888:
+    case QImage::Format_Grayscale8:
+    case QImage::Format_Grayscale16:
+    case QImage::Format_CMYK32:
+    case QImage::Format_Invalid:
+    case QImage::NImageFormats:
+        break;
+    }
+    return format; // No data-compatible alpha version
 }
 
 inline QImage::Format qt_opaqueVersionForPainting(QImage::Format format)
diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index cea7024aaa..f62373d4ef 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -3713,15 +3713,9 @@ bool QRasterPaintEnginePrivate::canUseImageBlitting(QPainter::CompositionMode mo
 
     QImage::Format dFormat = rasterBuffer->format;
     QImage::Format sFormat = image.format();
-    // Formats must match or source format must be a subset of destination format
-    if (dFormat != sFormat && image.pixelFormat().alphaUsage() == QPixelFormat::IgnoresAlpha) {
-        if ((sFormat == QImage::Format_RGB32 && dFormat == QImage::Format_ARGB32)
-            || (sFormat == QImage::Format_RGBX8888 && dFormat == QImage::Format_RGBA8888)
-            || (sFormat == QImage::Format_RGBX64 && dFormat == QImage::Format_RGBA64))
-            sFormat = dFormat;
-        else
-            sFormat = qt_maybeAlphaVersionWithSameDepth(sFormat); // this returns premul formats
-    }
+    // Formats must match or source format must be an opaque version of destination format
+    if (dFormat != sFormat && image.pixelFormat().alphaUsage() == QPixelFormat::IgnoresAlpha)
+        dFormat = qt_maybeDataCompatibleOpaqueVersion(dFormat);
     return (dFormat == sFormat);
 }
 
diff --git a/src/gui/painting/qrhibackingstore.cpp b/src/gui/painting/qrhibackingstore.cpp
index 72ab28f1fc..586dfb44a4 100644
--- a/src/gui/painting/qrhibackingstore.cpp
+++ b/src/gui/painting/qrhibackingstore.cpp
@@ -60,7 +60,7 @@ QImage::Format QRhiBackingStore::format() const
     // image must have an alpha channel. Hence upgrading the format. Matches
     // what other platforms (Windows, xcb) do.
     if (QImage::toPixelFormat(fmt).alphaUsage() != QPixelFormat::UsesAlpha)
-        fmt = qt_maybeAlphaVersionWithSameDepth(fmt);
+        fmt = qt_maybeDataCompatibleAlphaVersion(fmt);
 
     return fmt;
 }
diff --git a/src/plugins/platforms/windows/qwindowsbackingstore.cpp b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
index 0f9d0172d9..07918f6094 100644
--- a/src/plugins/platforms/windows/qwindowsbackingstore.cpp
+++ b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
@@ -117,7 +117,7 @@ void QWindowsBackingStore::resize(const QSize &size, const QRegion &region)
         if (QImage::toPixelFormat(format).alphaUsage() == QPixelFormat::UsesAlpha)
             m_alphaNeedsFill = true;
         else // upgrade but here we know app painting does not rely on alpha hence no need to fill
-            format = qt_maybeAlphaVersionWithSameDepth(format);
+            format = qt_maybeDataCompatibleAlphaVersion(format);
 
         QWindowsNativeImage *oldwni = m_image.data();
         auto *newwni = new QWindowsNativeImage(size.width(), size.height(), format);
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
index 0659cf9fc4..8353fac6a9 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
@@ -173,7 +173,7 @@ void QXcbBackingStoreImage::init(const QSize &size, uint depth, QImage::Format f
     m_qimage_format = format;
     m_hasAlpha = QImage::toPixelFormat(m_qimage_format).alphaUsage() == QPixelFormat::UsesAlpha;
     if (!m_hasAlpha)
-        m_qimage_format = qt_maybeAlphaVersionWithSameDepth(m_qimage_format);
+        m_qimage_format = qt_maybeDataCompatibleAlphaVersion(m_qimage_format);
 
     memset(&m_shm_info, 0, sizeof m_shm_info);