diff --git a/test/index_test.rb b/test/index_test.rb
index 73f61e9..c99a55b 100644
--- a/test/index_test.rb
+++ b/test/index_test.rb
@@ -85,7 +85,7 @@ class IndexTest < Minitest::Test
   def test_record_not_found
     store_names ["Product A", "Product B"]
     Product.where(name: "Product A").delete_all
-    assert_output nil, /\[searchkick\] WARNING: Records in search index do not exist in database\n/ do
+    assert_output nil, "[searchkick] WARNING: Records in search index do not exist in database\n" do
       assert_search "product", ["Product B"]
     end
   ensure
--
libgit2 0.21.0