1 files changed, 9 insertions, 1 deletions
diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index 2ae6602c82..a960d9d00f 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -1022,13 +1022,21 @@ assert_equal 'can not make a Proc shareable because it accesses outer variables
   end
 }
 
-# Ractor deep copies frozen objects
+# Ractor deep copies frozen objects (ary)
 assert_equal '[true, false]', %q{
   Ractor.new([[]].freeze) { |ary|
     [ary.frozen?, ary.first.frozen? ]
   }.take
 }
 
+# Ractor deep copies frozen objects (str)
+assert_equal '[true, false]', %q{
+  s = String.new.instance_eval { @x = []; freeze}
+  Ractor.new(s) { |s|
+    [s.frozen?, s.instance_variable_get(:@x).frozen?]
+  }.take
+}
+
 ###
 ### Synchronization tests
 ###