diff --git a/markdownserver/markdown_converter.py b/markdownserver/markdown_converter.py
index 22f43e8..5067575 100644
--- a/markdownserver/markdown_converter.py
+++ b/markdownserver/markdown_converter.py
@@ -1,6 +1,5 @@
 from __future__ import absolute_import, print_function
 
-import codecs
 import os
 import sys
 from builtins import object
@@ -12,23 +11,24 @@ from .env import css_path, html_dir, html_extension, ms_encoding
 
 class MarkdownConverter(object):
     def __init__(self):
-        css = codecs.open(css_path, encoding=ms_encoding, mode="r")
-        self.html_header = (
-            """
-            <html>
-            <head>
-            <style type='text/css'>
-            <!--
-            """
-            + css.read()
-            + """
-            //-->
-            </style>
-            </head>
-            <body>
-            <div class='markdown-body'>
-            """
-        )
+        with open(css_path, encoding=ms_encoding, mode="r") as css:
+            self.html_header = (
+                """
+                <html>
+                <head>
+                <style type='text/css'>
+                <!--
+                """
+                + css.read()
+                + """
+                //-->
+                </style>
+                </head>
+                <body>
+                <div class='markdown-body'>
+                """
+            )
+
         self.html_footer = """
             </div>
             </body>
@@ -36,7 +36,7 @@ class MarkdownConverter(object):
             """
 
     def convert(self, src, dst=""):
-        code = pycmarkgfm.markdown_to_html(self.read_md(src))
+        code = pycmarkgfm.gfm_to_html(self.read_md(src))
         return self.write_html(code, src, dst)
 
     def read_md(self, file_name):
