diff --git a/core/markdown.py b/core/markdown.py
new file mode 100644
index 00000000..da3432b9
--- /dev/null
+++ b/core/markdown.py
@@ -0,0 +1,37 @@
+import re
+from mistune import Renderer, InlineGrammar, InlineLexer, Markdown
+from django.core.urlresolvers import reverse_lazy, reverse
+
+
+class SithRenderer(Renderer):
+    def file_link(self, id, suffix):
+        return reverse('core:file_detail', kwargs={'file_id': id}) + suffix
+
+class SithInlineLexer(InlineLexer):
+    def enable_file_link(self):
+        # add file_link rules
+        self.rules.file_link = re.compile(
+            r'dfile://(\d*)/?(\S*)?'                   # dfile://4000/download
+        )
+        # Add file_link parser to default rules
+        # you can insert it some place you like
+        # but place matters, maybe 2 is not good
+        self.default_rules.insert(0, 'file_link')
+
+    def output_file_link(self, m):
+        id = m.group(1)
+        suffix = m.group(2) or ""
+        # you can create an custom render
+        # you can also return the html if you like
+        # return directly html like this:
+        # return reverse('core:file_detail', kwargs={'file_id': id}) + suffix
+        return self.renderer.file_link(id, suffix)
+
+renderer = SithRenderer()
+inline = SithInlineLexer(renderer)
+
+# enable the features
+inline.enable_file_link()
+markdown = Markdown(renderer, inline=inline)
+
+
diff --git a/core/templatetags/renderer.py b/core/templatetags/renderer.py
index ba2a4e1f..7fe51098 100644
--- a/core/templatetags/renderer.py
+++ b/core/templatetags/renderer.py
@@ -1,16 +1,15 @@
-import mistune
 from django import template
 from django.template.defaultfilters import stringfilter
 from django.utils.safestring import mark_safe
 from django.utils.html import escape
 
+from core.markdown import markdown as md
 
 register = template.Library()
 
 @register.filter(is_safe=False)
 @stringfilter
 def markdown(text):
-    md = mistune.Markdown()
     return mark_safe(md(escape(text)))
 
 @register.filter()