diff --git a/test/nbpm.get_port_number_test.exs b/test/nbpm.get_port_number_test.exs
index 29dc93d..2ace9ae 100644
--- a/test/nbpm.get_port_number_test.exs
+++ b/test/nbpm.get_port_number_test.exs
@@ -1,5 +1,5 @@
 defmodule Mix.Tasks.Nbpm.GetPortNumberTest do
-  use ExUnit.Case, async: true
+  use ExUnit.Case
   use Patch
 
   import ExUnit.CaptureIO