diff --git a/README.MacOS b/README.MacOS
index ff6bcba..0b6c1c3 100644
--- a/README.MacOS
+++ b/README.MacOS
@@ -40,7 +40,7 @@ crashes QScintilla.  The following patch needs to be applied to Qt:
      if(fi)
  	delete fi;
      qt_mac_current_painter = painter;
- #if defined(QT_THREAD_SUPPORT)
+ #if defined(TQT_THREAD_SUPPORT)
      if(qt_mac_port_mutex)
 -	qt_mac_port_mutex->unlock();
 +        qt_mac_port_mutex->unlock();