diff --git a/src/diff.h b/src/diff.h
index 83f6acb..da7ebe2 100644
--- a/src/diff.h
+++ b/src/diff.h
@@ -376,7 +376,7 @@ class MyPainter : public TQPainter
    int m_fontWidth;
 public:
    MyPainter(const TQPaintDevice* pd, bool bRTL, int width, int fontWidth) 
-   : TQPainter(const_cast<TQPaintDevice*>(TQT_TQPAINTDEVICE_CONST(pd)))
+   : TQPainter(pd)
    {
       if (bRTL) 
       {