diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index f8036795dc..e13b9f578c 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -1067,6 +1067,7 @@ q.pop
 
   def test_thread_name
     t = Thread.start {sleep}
+    sleep 0.001 until t.stop?
     assert_nil t.name
     s = t.inspect
     t.name = 'foo'