diff --git a/unix/vncviewer/DesktopWindow.cxx b/unix/vncviewer/DesktopWindow.cxx
index 36f96fc..095f14f 100644
--- a/unix/vncviewer/DesktopWindow.cxx
+++ b/unix/vncviewer/DesktopWindow.cxx
@@ -314,6 +314,7 @@
   damage.clear();
 
   im->put(win(), gc, r);
+  XFlush(dpy);
 }