diff --git a/django/contrib/markup/templatetags/markup.py b/django/contrib/markup/templatetags/markup.py
index 13708fd26d..5d4f4786e1 100644
--- a/django/contrib/markup/templatetags/markup.py
+++ b/django/contrib/markup/templatetags/markup.py
@@ -32,7 +32,23 @@ def textile(value):
         return mark_safe(force_unicode(textile.textile(smart_str(value), encoding='utf-8', output='utf-8')))
 textile.is_safe = True
 
-def markdown(value):
+def markdown(value, arg=''):
+    """
+    Runs Markdown over a given value, optionally using various
+    extensions python-markdown supports.
+
+    Syntax::
+
+        {{ value|markdown:"extension1_name,extension2_name..." }}
+
+    To enable safe mode, which strips raw HTML and only returns HTML
+    generated by actual Markdown syntax, pass "safe" as the first
+    extension in the list.
+
+    If the version of Markdown in use does not support extensions,
+    they will be silently ignored.
+
+    """
     try:
         import markdown
     except ImportError:
@@ -40,7 +56,18 @@ def markdown(value):
             raise template.TemplateSyntaxError, "Error in {% markdown %} filter: The Python markdown library isn't installed."
         return force_unicode(value)
     else:
-        return mark_safe(force_unicode(markdown.markdown(smart_str(value))))
+        # markdown.version was first added in 1.6b. The only version of markdown
+        # to fully support extensions before 1.6b was the shortlived 1.6a.
+        if hasattr(markdown, 'version'):
+            extensions = [e for e in arg.split(",") if e]
+            if len(extensions) > 0 and extensions[0] == "safe":
+                extensions = extensions[1:]
+                safe_mode = True
+            else:
+                safe_mode = False
+            return mark_safe(force_unicode(markdown.markdown(smart_str(value), extensions, safe_mode=safe_mode)))
+        else:
+            return mark_safe(force_unicode(markdown.markdown(smart_str(value))))
 markdown.is_safe = True
 
 def restructuredtext(value):