1 files changed, 16 insertions, 0 deletions
diff --git a/test/ruby/test_frozen.rb b/test/ruby/test_frozen.rb
index 2918a2afd8..6721cb1128 100644
--- a/test/ruby/test_frozen.rb
+++ b/test/ruby/test_frozen.rb
@@ -27,4 +27,20 @@ class TestFrozen < Test::Unit::TestCase
     str.freeze
     assert_raise(FrozenError) { str.instance_variable_set(:@b, 1) }
   end
+
+  def test_setting_ivar_on_frozen_string_with_singleton_class
+    str = "str"
+    str.singleton_class
+    str.freeze
+    assert_raise_with_message(FrozenError, "can't modify frozen String: \"str\"") { str.instance_variable_set(:@a, 1) }
+  end
+
+  class A
+    freeze
+  end
+
+  def test_setting_ivar_on_frozen_class
+    assert_raise_with_message(FrozenError, "can't modify frozen Class: TestFrozen::A") { A.instance_variable_set(:@a, 1) }
+    assert_raise_with_message(FrozenError, "can't modify frozen Class: #<Class:TestFrozen::A>") { A.singleton_class.instance_variable_set(:@a, 1) }
+  end
 end