1 files changed, 3 insertions, 2 deletions
diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp
index f40ca9d8b4..91214f27ca 100644
--- a/src/gui/painting/qtextureglyphcache.cpp
+++ b/src/gui/painting/qtextureglyphcache.cpp
@@ -341,9 +341,10 @@ void QImageTextureGlyphCache::fillTexture(const Coord &c, glyph_t g, QFixed subP
     } else if (m_format == QFontEngine::Format_Mono) {
         if (mask.depth() > 1) {
             // TODO optimize this
-            mask = mask.alphaChannel();
+            mask.convertTo(QImage::Format_Alpha8);
+            mask.reinterpretAsFormat(QImage::Format_Grayscale8);
             mask.invertPixels();
-            mask = mask.convertToFormat(QImage::Format_Mono, Qt::ThresholdDither);
+            mask.convertTo(QImage::Format_Mono, Qt::ThresholdDither);
         }
 
         int mw = qMin(mask.width(), c.w);