diff --git a/tests/do-arg.rkt b/tests/do-arg.rkt
new file mode 100644
index 0000000..3ceed51
--- /dev/null
+++ b/tests/do-arg.rkt
@@ -0,0 +1,4 @@
+#lang racket
+(require "../cover.rkt" racket/runtime-path rackunit)
+(define-runtime-path arg.rkt "arg.rkt")
+(check-true (test-files! (list (path->string arg.rkt) #("a"))))