1 files changed, 18 insertions, 0 deletions
diff --git a/test/ruby/test_pack.rb b/test/ruby/test_pack.rb
index 1ce46e8916..a0c66c188b 100644
--- a/test/ruby/test_pack.rb
+++ b/test/ruby/test_pack.rb
@@ -895,4 +895,22 @@ EXPECTED
     }
     assert_equal [nil], "a".unpack("C", offset: 1)
   end
+
+  def test_monkey_pack
+    assert_separately([], <<-'end;')
+      $-w = false
+      class Array
+        alias :old_pack :pack
+        def pack _; "oh no"; end
+      end
+
+      v = [2 ** 15].pack('n')
+
+      class Array
+        alias :pack :old_pack
+      end
+
+      assert_equal "oh no", v
+    end;
+  end
 end