diff --git a/lib/jekyll-feed/feed.xml b/lib/jekyll-feed/feed.xml
index 9068836f..e6d7f5df 100644
--- a/lib/jekyll-feed/feed.xml
+++ b/lib/jekyll-feed/feed.xml
@@ -91,7 +91,9 @@
       {% endif %}
 
       {% for tag in post.tags %}
-        <category term="{{ tag | xml_escape }}" />
+        {% unless post.categories contains tag %}      
+          <category term="{{ tag | xml_escape }}" />
+        {% endunless %}
       {% endfor %}
 
       {% assign post_summary = post.description | default: post.excerpt %}