diff --git a/test/lib/envutil.rb b/test/lib/envutil.rb
index 152ea741c9..dac59bd984 100644
--- a/test/lib/envutil.rb
+++ b/test/lib/envutil.rb
@@ -282,10 +282,7 @@ if defined?(RbConfig)
       attr_reader :ruby
     end
     dir = File.dirname(ruby)
-    name = File.basename(ruby, CONFIG['EXEEXT'])
     CONFIG['bindir'] = dir
-    CONFIG['ruby_install_name'] = name
-    CONFIG['RUBY_INSTALL_NAME'] = name
     Gem::ConfigMap[:bindir] = dir if defined?(Gem::ConfigMap)
   end
 end
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index 7f22df6479..caf00b2328 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -449,7 +449,8 @@ class TestRubyOptions < Test::Unit::TestCase
 
   def test_notfound
     notexist = "./notexist.rb"
-    rubybin = EnvUtil.rubybin.dup
+    dir, *rubybin = RbConfig::CONFIG.values_at('bindir', 'RUBY_INSTALL_NAME', 'EXEEXT')
+    rubybin = "#{dir}/#{rubybin.join('')}"
     rubybin.gsub!(%r(/), '\\') if /mswin|mingw/ =~ RUBY_PLATFORM
     rubybin = Regexp.quote(rubybin)
     pat = Regexp.quote(notexist)