diff --git a/test/ruby/test_require.rb b/test/ruby/test_require.rb
index 49afcceb33..bbec9a5f95 100644
--- a/test/ruby/test_require.rb
+++ b/test/ruby/test_require.rb
@@ -857,7 +857,13 @@ class TestRequire < Test::Unit::TestCase
         def to_path = @path
       end
 
-      def create_ruby_file = Tempfile.open(["test", ".rb"]).path
+      FILES = []
+
+      def create_ruby_file
+        file = Tempfile.open(["test", ".rb"])
+        FILES << file
+        file.path
+      end
 
       require MyString.new(create_ruby_file)
       $LOADED_FEATURES.unshift(create_ruby_file)