diff --git a/common/hw-gfx-gma-dp_aux_request.adb b/common/hw-gfx-gma-dp_aux_request.adb
index 97083b2..75a2cca 100644
--- a/common/hw-gfx-gma-dp_aux_request.adb
+++ b/common/hw-gfx-gma-dp_aux_request.adb
@@ -235,6 +235,8 @@
                Word32 ((Config.Default_CDClk_Freq + 1_000_000) / 2_000_000)
             else
                Word32 ((Config.Raw_Clock + 1_000_000) / 2_000_000))
+         elsif Config.Has_GMCH_RawClk then
+            Word32 (Div_Round_Closest (Config.Raw_Clock, 2_000_000))
          else 0);
 
       Busy : Boolean;