diff --git a/test/ruby/test_ractor.rb b/test/ruby/test_ractor.rb
index 74de2bf9cd..e2573153a3 100644
--- a/test/ruby/test_ractor.rb
+++ b/test/ruby/test_ractor.rb
@@ -164,6 +164,7 @@ class TestRactor < Test::Unit::TestCase
 
   # [Bug #21398]
   def test_port_receive_dnt_with_port_send
+    omit 'unstable on macos-14' if RUBY_PLATFORM =~ /darwin/
     assert_ractor(<<~'RUBY', timeout: 30)
       THREADS = 10
       JOBS_PER_THREAD = 50