diff --git a/CHANGELOG.md b/CHANGELOG.md
index eafa26d6..0cedddf4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+* Avoid mutating the options hash passed to a render object.
+
+  Refs #663.
+
+  *Max Schwenk*
+
 * Fix a segfault rendering quotes using `StripDown` and the `:quote`
   option.
 
diff --git a/test/custom_render_test.rb b/test/custom_render_test.rb
index 5f73c085..87c9f07c 100644
--- a/test/custom_render_test.rb
+++ b/test/custom_render_test.rb
@@ -23,7 +23,7 @@ def test_simple_overload
   end
 
   def test_renderer_options
-    parser = Redcarpet::Markdown.new(SimpleRender.new({ with_toc_data: true }.freeze), {})
+    parser = Redcarpet::Markdown.new(SimpleRender.new(with_toc_data: true))
     output = parser.render("# A title")
 
     assert_match "My little poney", output
@@ -36,6 +36,16 @@ def test_markdown_options
     assert_match "no_intra_emphasis", output
   end
 
+  def test_original_options_hash_is_not_mutated
+    options = { with_toc_data: true }
+    render  = SimpleRender.new(options)
+    parser  = Redcarpet::Markdown.new(render, tables: true)
+
+    computed_options = render.instance_variable_get(:"@options")
+
+    refute_equal computed_options.object_id, options.object_id
+  end
+
   class NilPreprocessRenderer < Redcarpet::Render::HTML
     def preprocess(fulldoc)
       nil