diff --git a/commonmarker-rouge.gemspec b/commonmarker-rouge.gemspec
index d931a1a..5f6cee8 100644
--- a/commonmarker-rouge.gemspec
+++ b/commonmarker-rouge.gemspec
@@ -20,7 +20,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '>= 2.0.0'
 
-  spec.add_dependency 'commonmarker', '> 0.8.0', '< 1.0'
+  spec.add_dependency 'commonmarker', '>= 0.14.5', '< 1.0'
   spec.add_dependency 'rouge',        '~> 1.10'
 
   spec.add_development_dependency 'bundler',  '~> 1.11'
diff --git a/lib/commonmarker/rouge.rb b/lib/commonmarker/rouge.rb
index b15c45a..b7299bc 100644
--- a/lib/commonmarker/rouge.rb
+++ b/lib/commonmarker/rouge.rb
@@ -7,7 +7,7 @@ module CommonMarker
   module Rouge
     module_function
 
-    def render_doc(text, cmark_options = :default, **highmark_options)
+    def render_doc(text, cmark_options = :DEFAULT, **highmark_options)
       cmark = highmark_options[:cmark_class] || ::CommonMarker
 
       ast = cmark.render_doc(text, cmark_options)
@@ -15,7 +15,7 @@ def render_doc(text, cmark_options = :default, **highmark_options)
       ast
     end
 
-    def render_html(text, cmark_options = :default)
+    def render_html(text, cmark_options = :DEFAULT)
       render_doc(text, cmark_options).to_html
     end