diff --git a/test/test_tmpdir.rb b/test/test_tmpdir.rb
index adc2918..c91fc33 100644
--- a/test/test_tmpdir.rb
+++ b/test/test_tmpdir.rb
@@ -134,17 +134,32 @@ def assert_mktmpdir_traversal
 
   def test_ractor
     assert_ractor(<<~'end;', require: "tmpdir")
-      r = Ractor.new do
-        Dir.mktmpdir() do |d|
-          Ractor.yield d
-          Ractor.receive
+      if defined?(Ractor::Port)
+        port = Ractor::Port.new
+        r = Ractor.new port do |port|
+          Dir.mktmpdir() do |d|
+            port << d
+            Ractor.receive
+          end
+        end
+        dir = port.receive
+        assert_file.directory? dir
+        r.send true
+        r.join
+        assert_file.not_exist? dir
+      else
+        r = Ractor.new do
+          Dir.mktmpdir() do |d|
+            Ractor.yield d
+            Ractor.receive
+          end
         end
+        dir = r.take
+        assert_file.directory? dir
+        r.send true
+        r.take
+        assert_file.not_exist? dir
       end
-      dir = r.take
-      assert_file.directory? dir
-      r.send true
-      r.take
-      assert_file.not_exist? dir
     end;
   end
 end