diff --git a/reading/exunit.livemd b/reading/exunit.livemd
index 5f6caf0f7..916bf711c 100644
--- a/reading/exunit.livemd
+++ b/reading/exunit.livemd
@@ -292,7 +292,7 @@ defmodule StringContainsTest do
 
   test "string contains hello" do
     string = "hello world"
-    string =~ "hello"
+    assert string =~ "hello"
   end
 end