1 files changed, 8 insertions, 0 deletions
diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index 95f2c89db4..fb2efec552 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -881,4 +881,12 @@ class TestThreadGroup < Test::Unit::TestCase
       Thread.current.join
     end
   end
+
+  def test_thread_join_main_thread
+    assert_raises(ThreadError) do
+      Thread.new(Thread.current) {|t|
+        t.join
+      }.join
+    end
+  end
 end