diff --git a/Directory.Packages.props b/Directory.Packages.props
index cb713801..ab079ca4 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>false</CentralPackageTransitivePinningEnabled>
-    <ToolingPackagesVersion>1.1.1.5540</ToolingPackagesVersion>
+    <ToolingPackagesVersion>1.1.1.17995</ToolingPackagesVersion>
     <AccessToNugetFeed>false</AccessToNugetFeed>
     <RestoreSources>
       https://api.nuget.org/v3/index.json;
diff --git a/EssentialCSharp.Web.Tests/SitemapXmlHelpersTests.cs b/EssentialCSharp.Web.Tests/SitemapXmlHelpersTests.cs
index 6c801d1e..be8edc90 100644
--- a/EssentialCSharp.Web.Tests/SitemapXmlHelpersTests.cs
+++ b/EssentialCSharp.Web.Tests/SitemapXmlHelpersTests.cs
@@ -197,49 +197,38 @@ public void GenerateSitemapXml_DoesNotIncludeErrorRoutes()
     }
 
     [Fact]
-    public void GenerateAndSerializeSitemapXml_CreatesFileSuccessfully()
+    public void GenerateSitemapXml_UsesLastModifiedDateFromSiteMapping()
     {
         // Arrange
-        var logger = _Factory.Services.GetRequiredService<ILogger<SitemapXmlHelpersTests>>();
         var tempDir = new DirectoryInfo(Path.GetTempPath());
-        var siteMappings = new List<SiteMapping> { CreateSiteMapping(1, 1, true) };
         var baseUrl = "https://test.example.com/";
+        var specificLastModified = new DateTime(2023, 5, 15, 10, 30, 0, DateTimeKind.Utc);
 
-        // Clean up any existing file
-        var expectedXmlPath = Path.Combine(tempDir.FullName, "sitemap.xml");
-        File.Delete(expectedXmlPath);
-
-        try
-        {
-            // Act
-            var routeConfigurationService = _Factory.Services.GetRequiredService<IRouteConfigurationService>();
-            SitemapXmlHelpers.GenerateAndSerializeSitemapXml(
-                tempDir,
-                siteMappings,
-                logger,
-                routeConfigurationService,
-                baseUrl);
-
-            // Assert
-            Assert.True(File.Exists(expectedXmlPath));
-
-            var xmlContent = File.ReadAllText(expectedXmlPath);
-            Assert.Contains("<?xml", xmlContent);
-            Assert.Contains("<urlset", xmlContent);
-            Assert.Contains(baseUrl, xmlContent);
-        }
-        finally
+        var siteMappings = new List<SiteMapping>
         {
-            // Clean up
-            File.Delete(expectedXmlPath);
-        }
+            CreateSiteMapping(1, 1, true, "test-page-1", specificLastModified)
+        };
+
+        // Act
+        var routeConfigurationService = _Factory.Services.GetRequiredService<IRouteConfigurationService>();
+        SitemapXmlHelpers.GenerateSitemapXml(
+            tempDir,
+            siteMappings,
+            routeConfigurationService,
+            baseUrl,
+            out var nodes);
+
+        // Assert
+        var siteMappingNode = nodes.First(node => node.Url.Contains("test-page-1"));
+        Assert.Equal(specificLastModified, siteMappingNode.LastModificationDate);
     }
 
     private static SiteMapping CreateSiteMapping(
         int chapterNumber,
         int pageNumber,
         bool includeInSitemapXml,
-        string key = "test-key")
+        string key = "test-key",
+        DateTime? lastModified = null)
     {
         return new SiteMapping(
             keys: [key],
@@ -253,7 +242,8 @@ private static SiteMapping CreateSiteMapping(
             anchorId: key,
             indentLevel: 1,
             contentHash: "TestHash123",
-            includeInSitemapXml: includeInSitemapXml
+            includeInSitemapXml: includeInSitemapXml,
+            lastModified: lastModified
         );
     }
 }
diff --git a/EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs b/EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs
index 0247b6f5..0032cf4a 100644
--- a/EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs
+++ b/EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs
@@ -68,7 +68,7 @@ public static void GenerateSitemapXml(DirectoryInfo wwwrootDirectory, List<SiteM
         // Add site mappings from content
         nodes.AddRange(siteMappings.Where(item => item.IncludeInSitemapXml).Select<SiteMapping, SitemapNode>(siteMapping => new($"{baseUrl.TrimEnd('/')}/{siteMapping.Keys.First()}")
         {
-            LastModificationDate = newDateTime,
+            LastModificationDate = siteMapping.LastModified ?? newDateTime,
             ChangeFrequency = ChangeFrequency.Daily,
             Priority = 0.8M
         }));