diff --git a/spec/center_spec.exs b/spec/center_spec.exs
index a027de5..666f268 100644
--- a/spec/center_spec.exs
+++ b/spec/center_spec.exs
@@ -1,5 +1,5 @@
 defmodule CenterSpec do
-  use ESpec
+  use ESpec, async: true
 
   describe "" do
     it "center/3" do