diff --git a/luamd b/luamd
index 8d89984..0185c28 100755
--- a/luamd
+++ b/luamd
@@ -65,7 +65,7 @@ local md_options = {
prependHead = "",
appendTail = "",
tag = "body",
- insertHead = string.format("%s", file),
+ insertHead = string.format("%s", ARGV[argidx] or ""),
}
if ARGV[argidx] and ARGV[argidx] ~= "" then
local file = nil