diff --git a/src/SitemapRotator.js b/src/SitemapRotator.js
index 25e093f..28bc255 100644
--- a/src/SitemapRotator.js
+++ b/src/SitemapRotator.js
@@ -19,7 +19,16 @@ module.exports = function SitemapRotator(
     }, []);
 
   // adds url to stream
-  const addURL = (url, depth, lastMod = getCurrentDateTime()) => {
+  const addURL = (url, depth, lastMod = getCurrentDateTime(), baseUrl) => {
+    if (baseUrl) {
+      const urlInstance = new URL(url);
+      const baseUrlInstance = new URL(baseUrl);
+      urlInstance.protocol = baseUrlInstance.protocol;
+      urlInstance.host = baseUrlInstance.host;
+      urlInstance.port = baseUrlInstance.port;
+      url = urlInstance.href;
+    }
+
     const currentDateTime = lastModEnabled ? lastMod : null;
 
     // exclude existing sitemap.xml
diff --git a/src/index.js b/src/index.js
index 6213136..2c9a727 100644
--- a/src/index.js
+++ b/src/index.js
@@ -29,7 +29,8 @@ module.exports = function SitemapGenerator(uri, opts) {
     changeFreq: '',
     priorityMap: [],
     ignoreAMP: true,
-    ignore: null
+    ignore: null,
+    baseUrl: null
   };
 
   if (!uri) {
@@ -109,7 +110,12 @@ module.exports = function SitemapGenerator(uri, opts) {
       if (sitemapPath !== null) {
         // eslint-disable-next-line
         const lastMod = queueItem.stateData.headers['last-modified'];
-        sitemap.addURL(url, depth, lastMod && format(lastMod, 'YYYY-MM-DD'));
+        sitemap.addURL(
+          url,
+          depth,
+          lastMod && format(lastMod, 'YYYY-MM-DD'),
+          opts.baseUrl
+        );
       }
     }
   });