diff --git a/common/hw-gfx-edid.ads b/common/hw-gfx-edid.ads
index efc3b36..cce1a40 100644
--- a/common/hw-gfx-edid.ads
+++ b/common/hw-gfx-edid.ads
@@ -32,6 +32,13 @@
    with
       Pre => Offset < Raw_EDID_Index'Last;
 
+   function Compatible_Display
+     (Raw_EDID : Raw_EDID_Data;
+      Display  : Display_Type)
+      return Boolean
+   with
+      Pre => Valid (Raw_EDID);
+
    function Has_Preferred_Mode (Raw_EDID : Raw_EDID_Data) return Boolean
    with
       Pre => Valid (Raw_EDID),