1 files changed, 8 insertions, 0 deletions
diff --git a/spec/ruby/core/matchdata/post_match_spec.rb b/spec/ruby/core/matchdata/post_match_spec.rb
index 4ae51f107e..1a4ca0a83f 100644
--- a/spec/ruby/core/matchdata/post_match_spec.rb
+++ b/spec/ruby/core/matchdata/post_match_spec.rb
@@ -1,4 +1,5 @@
 require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
 
 describe "MatchData#post_match" do
   it "returns the string after the match equiv. special var $'" do
@@ -33,4 +34,11 @@ describe "MatchData#post_match" do
     str = "abc".force_encoding Encoding::ISO_8859_1
     str.match(/c/).post_match.encoding.should equal(Encoding::ISO_8859_1)
   end
+
+  ruby_version_is "3.0" do
+    it "returns an instance of String when given a String subclass" do
+      str = MatchDataSpecs::MyString.new("THX1138: The Movie")
+      /(.)(.)(\d+)(\d)/.match(str).post_match.should be_an_instance_of(String)
+    end
+  end
 end