1 files changed, 6 insertions, 0 deletions
diff --git a/test/test_tmpdir.rb b/test/test_tmpdir.rb
index 3bdce3542c..62b4abfa1a 100644
--- a/test/test_tmpdir.rb
+++ b/test/test_tmpdir.rb
@@ -30,4 +30,10 @@ class TestTmpdir < Test::Unit::TestCase
     ENV["HOME"] = home
     Dir.rmdir(dir) if dir
   end
+
+  def test_mktmpdir_nil
+    Dir.mktmpdir(nil) {|d|
+      assert_kind_of(String, d)
+    }
+  end
 end