diff --git a/DNN Platform/Library/Services/Sitemap/CoreSitemapProvider.cs b/DNN Platform/Library/Services/Sitemap/CoreSitemapProvider.cs
index aebc26b05e6..043fe3286ff 100644
--- a/DNN Platform/Library/Services/Sitemap/CoreSitemapProvider.cs	
+++ b/DNN Platform/Library/Services/Sitemap/CoreSitemapProvider.cs	
@@ -126,6 +126,51 @@ private SitemapUrl GetPageUrl(TabInfo objTab, string language)
             }
             pageUrl.ChangeFrequency = SitemapChangeFrequency.Daily;
 
+            // support for alternate pages: https://support.google.com/webmasters/answer/2620865?hl=en
+            if (ps.ContentLocalizationEnabled && !objTab.IsNeutralCulture)
+            {
+                List<AlternateUrl> alternates = new List<AlternateUrl>();
+                TabInfo currentTab = objTab;
+
+                if (!objTab.IsDefaultLanguage)
+                    currentTab = objTab.DefaultLanguageTab;
+
+                foreach (TabInfo localized in currentTab.LocalizedTabs.Values)
+                {
+                    if ((!localized.IsDeleted && !localized.DisableLink && localized.TabType == TabType.Normal) &&
+                        (Null.IsNull(localized.StartDate) || localized.StartDate < DateTime.Now) &&
+                        (Null.IsNull(localized.EndDate) || localized.EndDate > DateTime.Now) &&
+                        (IsTabPublic(localized.TabPermissions)) &&
+                        (includeHiddenPages || localized.IsVisible))
+                    {
+                        string alternateUrl = Globals.NavigateURL(localized.TabID, localized.IsSuperTab, ps, "", localized.CultureCode);
+
+                        if (alternateUrl.ToLower().IndexOf(portalAlias.ToLower(), StringComparison.Ordinal) == -1)
+                        {
+                            // code to fix a bug in dnn5.1.2 for navigateurl
+                            if ((HttpContext.Current != null))
+                            {
+                                alternateUrl = Globals.AddHTTP(HttpContext.Current.Request.Url.Host + alternateUrl);
+                            }
+                            else
+                            {
+                                // try to use the portalalias
+                                alternateUrl = Globals.AddHTTP(portalAlias.ToLower()) + alternateUrl;
+                            }
+                        }
+                        alternates.Add(new AlternateUrl() { Url = alternateUrl, Language = localized.CultureCode });
+                    }
+                }
+
+                if (alternates.Count > 0)
+                {
+                    // add self to the list
+                    alternates.Add(new AlternateUrl() { Url = pageUrl.Url, Language = objTab.CultureCode });
+
+                    pageUrl.AlternateUrls = alternates;
+                }
+            }
+
             return pageUrl;
         }
 
@@ -150,7 +195,7 @@ protected float GetPriority(TabInfo objTab)
                 }
                 else
                 {
-                    priority = Convert.ToSingle(1 - (objTab.Level*0.1));
+                    priority = Convert.ToSingle(1 - (objTab.Level * 0.1));
                 }
 
                 if (priority < minPagePriority)
@@ -173,7 +218,7 @@ public virtual bool IsTabPublic(TabPermissionCollection objTabPermissions)
             if ((roles != null))
             {
                 // permissions strings are encoded with Deny permissions at the beginning and Grant permissions at the end for optimal performance
-                foreach (string role in roles.Split(new[] {';'}))
+                foreach (string role in roles.Split(new[] { ';' }))
                 {
                     if (!string.IsNullOrEmpty(role))
                     {
diff --git a/DNN Platform/Library/Services/Sitemap/SitemapBuilder.cs b/DNN Platform/Library/Services/Sitemap/SitemapBuilder.cs
index 3c7693539c6..5e5a0a96b18 100644
--- a/DNN Platform/Library/Services/Sitemap/SitemapBuilder.cs	
+++ b/DNN Platform/Library/Services/Sitemap/SitemapBuilder.cs	
@@ -220,6 +220,7 @@ private void WriteSitemap(bool cached, TextWriter output, int index, List<Sitema
             // build header
             writer.WriteStartElement("urlset", "http://www.sitemaps.org/schemas/sitemap/" + SITEMAP_VERSION);
             writer.WriteAttributeString("xmlns", "xsi", null, "http://www.w3.org/2001/XMLSchema-instance");
+            writer.WriteAttributeString("xmlns", "xhtml", null, "http://www.w3.org/1999/xhtml");
             var schemaLocation = "http://www.sitemaps.org/schemas/sitemap/" + SITEMAP_VERSION;
             writer.WriteAttributeString("xsi", "schemaLocation", null, string.Format("{0} {0}/sitemap.xsd", schemaLocation));
 
@@ -300,6 +301,18 @@ private void AddURL(SitemapUrl sitemapUrl)
             writer.WriteElementString("lastmod", sitemapUrl.LastModified.ToString("yyyy-MM-dd"));
             writer.WriteElementString("changefreq", sitemapUrl.ChangeFrequency.ToString().ToLower());
             writer.WriteElementString("priority", sitemapUrl.Priority.ToString("F01", CultureInfo.InvariantCulture));
+
+            if (sitemapUrl.AlternateUrls != null)
+            {
+                foreach (AlternateUrl alternate in sitemapUrl.AlternateUrls)
+                {
+                    writer.WriteStartElement("link", "http://www.w3.org/1999/xhtml");
+                    writer.WriteAttributeString("rel", "alternate");
+                    writer.WriteAttributeString("hreflang", alternate.Language);
+                    writer.WriteAttributeString("href", alternate.Url);
+                    writer.WriteEndElement();
+                }
+            }
             writer.WriteEndElement();
         }
 
diff --git a/DNN Platform/Library/Services/Sitemap/SitemapUrl.cs b/DNN Platform/Library/Services/Sitemap/SitemapUrl.cs
index 20ba9366fe6..b73b4595c44 100644
--- a/DNN Platform/Library/Services/Sitemap/SitemapUrl.cs	
+++ b/DNN Platform/Library/Services/Sitemap/SitemapUrl.cs	
@@ -21,6 +21,7 @@
 #region Usings
 
 using System;
+using System.Collections.Generic;
 
 #endregion
 
@@ -30,13 +31,19 @@ public class SitemapUrl
     {
         public string Url { get; set; }
 
-
         public DateTime LastModified { get; set; }
 
-
         public SitemapChangeFrequency ChangeFrequency { get; set; }
 
-
         public float Priority { get; set; }
+
+        public List<AlternateUrl> AlternateUrls { get; set; }
+    }
+
+    public class AlternateUrl
+    {
+        public string Language { get; set; }
+
+        public string Url { get; set; }
     }
 }
\ No newline at end of file