diff --git a/components/templates/src/builtins/rss.xml b/components/templates/src/builtins/rss.xml
index d208aa7..8f88973 100644
--- a/components/templates/src/builtins/rss.xml
+++ b/components/templates/src/builtins/rss.xml
@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0">
     <channel>
         <title>{{ config.title }}</title>
diff --git a/components/templates/src/builtins/sitemap.xml b/components/templates/src/builtins/sitemap.xml
index 2154a5b..54cbee7 100644
--- a/components/templates/src/builtins/sitemap.xml
+++ b/components/templates/src/builtins/sitemap.xml
@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <urlset xmlns="https://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
     {% for sitemap_entry in entries %}
         <url>
diff --git a/components/templates/src/builtins/split_sitemap_index.xml b/components/templates/src/builtins/split_sitemap_index.xml
index 171665c..44b8c12 100644
--- a/components/templates/src/builtins/split_sitemap_index.xml
+++ b/components/templates/src/builtins/split_sitemap_index.xml
@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <sitemapindex xmlns="https://www.sitemaps.org/schemas/sitemap/0.9/siteindex.xsd">
     {% for sitemap in sitemaps %}
         <sitemap>