diff --git a/Library/Homebrew/test/test_integration_cmds.rb b/Library/Homebrew/test/test_integration_cmds.rb
index 19a2372d7c..d72cc16b52 100644
--- a/Library/Homebrew/test/test_integration_cmds.rb
+++ b/Library/Homebrew/test/test_integration_cmds.rb
@@ -65,7 +65,7 @@ class IntegrationCommandTests < Homebrew::TestCase
   end
 
   def test_env
-    assert_match /CMAKE_PREFIX_PATH="#{HOMEBREW_PREFIX}[:"]/,
+    assert_match %r{CMAKE_PREFIX_PATH="#{HOMEBREW_PREFIX}[:"]},
                  cmd("--env")
   end