diff --git a/pelican/themes/simple/templates/base.html b/pelican/themes/simple/templates/base.html
index a1fdcf78..4fde8de5 100644
--- a/pelican/themes/simple/templates/base.html
+++ b/pelican/themes/simple/templates/base.html
@@ -17,16 +17,16 @@
         <link href="{{ FEED_DOMAIN }}/{% if FEED_RSS_URL %}{{ FEED_RSS_URL }}{% else %}{{ FEED_RSS }}{% endif %}" type="application/rss+xml" rel="alternate" title="{{ SITENAME }} RSS Feed" />
         {% endif %}
         {% if CATEGORY_FEED_ATOM and category %}
-        <link href="{{ FEED_DOMAIN }}/{% if CATEGORY_FEED_ATOM_URL %}{{ CATEGORY_FEED_ATOM_URL|format(category.slug) }}{% else %}{{ CATEGORY_FEED_ATOM|format(category.slug) }}{% endif %}" type="application/atom+xml" rel="alternate" title="{{ SITENAME }} Categories Atom Feed" />
+        <link href="{{ FEED_DOMAIN }}/{% if CATEGORY_FEED_ATOM_URL %}{{ CATEGORY_FEED_ATOM_URL.format(slug=category.slug) }}{% else %}{{ CATEGORY_FEED_ATOM.format(slug=category.slug) }}{% endif %}" type="application/atom+xml" rel="alternate" title="{{ SITENAME }} Categories Atom Feed" />
         {% endif %}
         {% if CATEGORY_FEED_RSS and category %}
-        <link href="{{ FEED_DOMAIN }}/{% if CATEGORY_FEED_RSS_URL %}{{ CATEGORY_FEED_RSS_URL|format(category.slug) }}{% else %}{{ CATEGORY_FEED_RSS|format(category.slug) }}{% endif %}" type="application/rss+xml" rel="alternate" title="{{ SITENAME }} Categories RSS Feed" />
+        <link href="{{ FEED_DOMAIN }}/{% if CATEGORY_FEED_RSS_URL %}{{ CATEGORY_FEED_RSS_URL.format(slug=category.slug) }}{% else %}{{ CATEGORY_FEED_RSS.format(slug=category.slug) }}{% endif %}" type="application/rss+xml" rel="alternate" title="{{ SITENAME }} Categories RSS Feed" />
         {% endif %}
         {% if TAG_FEED_ATOM and tag %}
-        <link href="{{ FEED_DOMAIN }}/{% if TAG_FEED_ATOM_URL %}{{ TAG_FEED_ATOM_URL|format(tag.slug) }}{% else %}{{ TAG_FEED_ATOM|format(tag.slug) }}{% endif %}" type="application/atom+xml" rel="alternate" title="{{ SITENAME }} Tags Atom Feed" />
+        <link href="{{ FEED_DOMAIN }}/{% if TAG_FEED_ATOM_URL %}{{ TAG_FEED_ATOM_URL.format(slug=tag.slug) }}{% else %}{{ TAG_FEED_ATOM.format(slug=tag.slug) }}{% endif %}" type="application/atom+xml" rel="alternate" title="{{ SITENAME }} Tags Atom Feed" />
         {% endif %}
         {% if TAG_FEED_RSS and tag %}
-        <link href="{{ FEED_DOMAIN }}/{% if TAG_FEED_RSS_URL %}{{ TAG_FEED_RSS_URL|format(tag.slug) }}{% else %}{{ TAG_FEED_RSS|format(tag.slug) }}{% endif %}" type="application/rss+xml" rel="alternate" title="{{ SITENAME }} Tags RSS Feed" />
+        <link href="{{ FEED_DOMAIN }}/{% if TAG_FEED_RSS_URL %}{{ TAG_FEED_RSS_URL.format(slug=tag.slug) }}{% else %}{{ TAG_FEED_RSS.format(slug=tag.slug) }}{% endif %}" type="application/rss+xml" rel="alternate" title="{{ SITENAME }} Tags RSS Feed" />
         {% endif %}
         {% endblock head %}
 </head>