diff --git a/app/code/Magento/Sitemap/Model/Sitemap.php b/app/code/Magento/Sitemap/Model/Sitemap.php
index 515caebe1ef27..f6a5f029eafca 100644
--- a/app/code/Magento/Sitemap/Model/Sitemap.php
+++ b/app/code/Magento/Sitemap/Model/Sitemap.php
@@ -43,6 +43,11 @@ class Sitemap extends \Magento\Framework\Model\AbstractModel implements \Magento
 
     const TYPE_URL = 'url';
 
+    /**
+     * Last mode date min value
+     */
+    const LAST_MOD_MIN_VAL = '0000-01-01 00:00:00';
+
     /**
      * Real file path
      *
@@ -157,6 +162,13 @@ class Sitemap extends \Magento\Framework\Model\AbstractModel implements \Magento
      */
     protected $_cacheTag = true;
 
+    /**
+     * Last mode min timestamp value
+     *
+     * @var int
+     */
+    private $lastModMinTsVal;
+
     /**
      * Initialize dependencies.
      *
@@ -661,7 +673,11 @@ protected function _getMediaUrl($url)
      */
     protected function _getFormattedLastmodDate($date)
     {
-        return date('c', strtotime($date));
+        if ($this->lastModMinTsVal === null) {
+            $this->lastModMinTsVal = strtotime(self::LAST_MOD_MIN_VAL);
+        }
+        $timestamp = max(strtotime($date), $this->lastModMinTsVal);
+        return date('c', $timestamp);
     }
 
     /**
diff --git a/app/code/Magento/Sitemap/Test/Unit/Model/SitemapTest.php b/app/code/Magento/Sitemap/Test/Unit/Model/SitemapTest.php
index 40b72cbd53c00..83210c5789776 100644
--- a/app/code/Magento/Sitemap/Test/Unit/Model/SitemapTest.php
+++ b/app/code/Magento/Sitemap/Test/Unit/Model/SitemapTest.php
@@ -540,7 +540,7 @@ protected function _getModelMock($mockBeforeSave = false)
             $this->returnValue(
                 [
                     new \Magento\Framework\DataObject(
-                        ['url' => 'product.html', 'updated_at' => '2012-12-21 00:00:00']
+                        ['url' => 'product.html', 'updated_at' => '0000-00-00 00:00:00']
                     ),
                     new \Magento\Framework\DataObject(
                         [
diff --git a/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-1-3.xml b/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-1-3.xml
index 3a0357cf30c51..519464cf76cf1 100644
--- a/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-1-3.xml
+++ b/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-1-3.xml
@@ -10,7 +10,7 @@
         xmlns:image="http://www.google.com/schemas/sitemap-image/1.1">
     <url>
         <loc>http://store.com/product.html</loc>
-        <lastmod>2012-12-21T00:00:00-08:00</lastmod>
+        <lastmod>0000-01-01T00:00:00-08:00</lastmod>
         <changefreq>monthly</changefreq>
         <priority>0.5</priority>
     </url>
diff --git a/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-single.xml b/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-single.xml
index e79e022c98995..cc2ff96dd28f2 100644
--- a/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-single.xml
+++ b/app/code/Magento/Sitemap/Test/Unit/Model/_files/sitemap-single.xml
@@ -22,7 +22,7 @@
     </url>
     <url>
         <loc>http://store.com/product.html</loc>
-        <lastmod>2012-12-21T00:00:00-08:00</lastmod>
+        <lastmod>0000-01-01T00:00:00-08:00</lastmod>
         <changefreq>monthly</changefreq>
         <priority>0.5</priority>
     </url>