1 files changed, 2 insertions, 2 deletions
diff --git a/test/psych/test_tainted.rb b/test/psych/test_tainted.rb
index 870583323d..dcf150b138 100644
--- a/test/psych/test_tainted.rb
+++ b/test/psych/test_tainted.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 require_relative 'helper'
 
 module Psych
@@ -90,7 +90,7 @@ module Psych
     end
 
     def assert_taintedness string
-      @parser.parse string.taint
+      @parser.parse string.dup.taint
     end
   end