diff --git a/lumps/dmxgus/gen-ultramid b/lumps/dmxgus/gen-ultramid
index 52c2eaaa..a7c06cad 100755
--- a/lumps/dmxgus/gen-ultramid
+++ b/lumps/dmxgus/gen-ultramid
@@ -158,7 +158,8 @@ mappings = (
 
 with open(sys.argv[1], "w") as output:
 	output.write("# Freedoom GUS config.\n"
-	             "# Autogenerated by gen-ultramid\n\n")
+	             "# Autogenerated by the gen-ultramid script.\n"
+		     "# Please do not manually edit this file!\n")
 
 	for instr_id, name in sorted(config.GUS_INSTR_PATCHES.items()):
 		line = "%i, %i, %i, %i, %i, %s" % (