diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index 4383795dc1..ea7c2c197d 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -1532,7 +1532,7 @@ assert_equal "ok", %q{
 
   1_000.times { idle_worker, tmp_reporter = Ractor.select(*workers) }
   "ok"
-} unless ENV['RUN_OPTS'] =~ /rjit/ # flaky
+} unless ENV['RUN_OPTS'] =~ /rjit/ || ENV.key?('CI') # flaky
 
 assert_equal "ok", %q{
   def foo(*); ->{ super }; end