diff --git a/honk.go b/honk.go
index 8dbc0f5..12cf27e 100644
--- a/honk.go
+++ b/honk.go
@@ -957,6 +957,7 @@ func servefile(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	w.Header().Set("Content-Type", media)
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Cache-Control", "max-age="+somedays())
 	w.Write(data)
 }