diff --git a/tests/fixme.sh b/tests/fixme.sh
index 14316a5..e5c85e3 100755
--- a/tests/fixme.sh
+++ b/tests/fixme.sh
@@ -122,7 +122,7 @@ _fixme_callback()
 			echo "_fixme_callback_python"
 			return 0
 			;;
-		"<html"*|"<?xml"*)
+		"<!DOCTYPE"*|"<!doctype"*|"<HTML"*|"<html"*|"<?xml"*)
 			echo "_fixme_callback_xml"
 			return 0
 			;;