1 files changed, 3 insertions, 1 deletions
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index 4a3599c7d3..0f697f949f 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -968,8 +968,10 @@ class TestRubyOptions < Test::Unit::TestCase
       [["disable", "false"], ["enable", "true"]].each do |opt, exp|
         %W[frozen_string_literal frozen-string-literal].each do |arg|
           key = "#{opt}=#{arg}"
+          negopt = exp ? "disable" : "enable"
+          env = {"RUBYOPT"=>"--#{negopt}=#{arg}"}
           a.for(key) do
-            assert_in_out_err(["--disable=gems", "--#{key}"], 'p("foo".frozen?)', [exp])
+            assert_in_out_err([env, "--disable=gems", "--#{key}"], 'p("foo".frozen?)', [exp])
           end
         end
       end