diff --git a/src/etc/xpra/xorg.conf b/src/etc/xpra/xorg.conf
index b38591c96c..1388516ee9 100644
--- a/src/etc/xpra/xorg.conf
+++ b/src/etc/xpra/xorg.conf
@@ -14,6 +14,7 @@ EndSection
 Section "Device"
   Identifier "dummy_videocard"
   Driver "dummy"
+  DacSpeed 600
   Option "ConstantDPI" "true"
   #VideoRam 2048000
   #VideoRam 1024000