diff --git a/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/.template.config/template.json b/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/.template.config/template.json
index caeceae1dde..d95f7c41c13 100644
--- a/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/.template.config/template.json
+++ b/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/.template.config/template.json
@@ -499,6 +499,12 @@
       "valueTransform": "vectorStoreIndexNameTransform",
       "replaces": "data-ChatWithCustomData-CSharp.Web-"
     },
+    "aspireClassNameReplacer": {
+      "type": "derived",
+      "valueSource": "name",
+      "valueTransform": "aspireClassName_ReplaceInvalidChars",
+      "replaces": "ChatWithCustomData_CSharp_Web_AspireClassName"
+    },
     "webProjectNamespaceAdjuster": {
       "type": "generated",
       "generator": "switch",
@@ -524,6 +530,12 @@
     }
   },
   "forms": {
+    "aspireClassName_ReplaceInvalidChars": {
+      "identifier": "replace",
+      "pattern": "(((?<=\\.)|^)(?=\\d)|\\W)",
+      "replacement": "_",
+      "description": "Insert underscore before digits at start, or after a dot, or to replace non-word characters"
+    },
     "vectorStoreIndexNameTransform": {
       "identifier": "chain",
       "steps": [
diff --git a/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/ChatWithCustomData-CSharp.AppHost/Program.cs b/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/ChatWithCustomData-CSharp.AppHost/Program.cs
index c3045240cda..df2f6765d9e 100644
--- a/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/ChatWithCustomData-CSharp.AppHost/Program.cs
+++ b/src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/ChatWithCustomData/ChatWithCustomData-CSharp.AppHost/Program.cs
@@ -51,7 +51,7 @@
 #else // UseLocalVectorStore
 #endif
 
-var webApp = builder.AddProject<Projects.ChatWithCustomData_CSharp_Web>("aichatweb-app");
+var webApp = builder.AddProject<Projects.ChatWithCustomData_CSharp_Web_AspireClassName_Web>("aichatweb-app");
 #if (IsOllama) // AI SERVICE PROVIDER REFERENCES
 webApp
     .WithReference(chat)
diff --git a/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/AIChatWebExecutionTests.cs b/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/AIChatWebExecutionTests.cs
index 1b8c4177f40..f5d2bc52e3a 100644
--- a/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/AIChatWebExecutionTests.cs
+++ b/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/AIChatWebExecutionTests.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Microsoft.TestUtilities;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -71,6 +72,44 @@ public async Task CreateRestoreAndBuild_AspireTemplate(params string[] args)
         await Fixture.BuildProjectAsync(project);
     }
 
+    /// <summary>
+    /// Runs a single test with --aspire true and a project name that will trigger the class
+    /// name normalization bug reported in https://github.com/dotnet/extensions/issues/6811.
+    /// </summary>
+    [Fact]
+    public async Task CreateRestoreAndBuild_AspireProjectName()
+    {
+        await CreateRestoreAndBuild_AspireProjectName_Variants("azureopenai", "mix.ed-dash_name 123");
+    }
+
+    /// <summary>
+    /// Tests build for various project name formats, including dots and other
+    /// separators, to trigger the class name normalization bug described
+    /// in https://github.com/dotnet/extensions/issues/6811
+    /// This runs for all provider combinations with --aspire true and different
+    /// project names to ensure the bug is caught in all scenarios.
+    /// </summary>
+    /// <remarks>
+    /// Because this test takes a long time to run, it is skipped by default. Set the
+    /// environment variable <c>AI_TEMPLATES_TEST_PROJECT_NAMES</c> to "true" or "1"
+    /// to enable it.
+    /// </remarks>
+    [ConditionalTheory]
+    [EnvironmentVariableCondition("AI_TEMPLATES_TEST_PROJECT_NAMES", "true", "1")]
+    [MemberData(nameof(GetAspireProjectNameVariants))]
+    public async Task CreateRestoreAndBuild_AspireProjectName_Variants(string provider, string projectName)
+    {
+        var project = await Fixture.CreateProjectAsync(
+            templateName: "aichatweb",
+            projectName: projectName,
+            args: new[] { "--aspire", $"--provider={provider}" });
+
+        project.StartupProjectRelativePath = $"{projectName}.AppHost";
+
+        await Fixture.RestoreProjectAsync(project);
+        await Fixture.BuildProjectAsync(project);
+    }
+
     private static readonly (string name, string[] values)[] _templateOptions = [
         ("--provider",          ["azureopenai", "githubmodels", "ollama", "openai"]),
         ("--vector-store",      ["azureaisearch", "local", "qdrant"]),
@@ -158,4 +197,26 @@ private static IEnumerable<string[]> GetAllPossibleOptions(ReadOnlyMemory<(strin
             }
         }
     }
+
+    public static IEnumerable<object[]> GetAspireProjectNameVariants()
+    {
+        foreach (string provider in new[] { "ollama", "openai", "azureopenai", "githubmodels" })
+        {
+            foreach (string projectName in new[]
+            {
+                "mix.ed-dash_name 123",
+                "dot.name",
+                "project.123",
+                "space name",
+                ".1My.Projec-",
+                "1Project123",
+                "11double",
+                "1",
+                "nomatch"
+            })
+            {
+                yield return new object[] { provider, projectName };
+            }
+        }
+    }
 }
diff --git a/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/Microsoft.Extensions.AI.Templates.Tests.csproj b/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/Microsoft.Extensions.AI.Templates.Tests.csproj
index d2fc26ea0ab..e4c52714b79 100644
--- a/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/Microsoft.Extensions.AI.Templates.Tests.csproj
+++ b/test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/Microsoft.Extensions.AI.Templates.Tests.csproj
@@ -15,6 +15,10 @@
     <PackageReference Include="Microsoft.TemplateEngine.TestHelper" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\TestUtilities\TestUtilities.csproj" />
+  </ItemGroup>
+
   <ItemGroup>
     <Compile Remove="Snapshots\**\*.*" />
     <None Include="Snapshots\**\*.*" />
diff --git a/test/TestUtilities/XUnit/EnvironmentVariableConditionAttribute.cs b/test/TestUtilities/XUnit/EnvironmentVariableConditionAttribute.cs
new file mode 100644
index 00000000000..45a54409047
--- /dev/null
+++ b/test/TestUtilities/XUnit/EnvironmentVariableConditionAttribute.cs
@@ -0,0 +1,86 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Linq;
+
+namespace Microsoft.TestUtilities;
+
+/// <summary>
+/// Skips a test based on the value of an environment variable.
+/// </summary>
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class | AttributeTargets.Assembly, AllowMultiple = true)]
+public class EnvironmentVariableConditionAttribute : Attribute, ITestCondition
+{
+    private string? _currentValue;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="EnvironmentVariableConditionAttribute"/> class.
+    /// </summary>
+    /// <param name="variableName">Name of the environment variable.</param>
+    /// <param name="values">Value(s) of the environment variable to match for the condition.</param>
+    /// <remarks>
+    /// By default, the test will be run if the value of the variable matches any of the supplied values.
+    /// Set <see cref="RunOnMatch"/> to <c>False</c> to run the test only if the value does not match.
+    /// </remarks>
+    public EnvironmentVariableConditionAttribute(string variableName, params string[] values)
+    {
+        if (string.IsNullOrEmpty(variableName))
+        {
+            throw new ArgumentException("Value cannot be null or empty.", nameof(variableName));
+        }
+
+        if (values == null || values.Length == 0)
+        {
+            throw new ArgumentException("You must supply at least one value to match.", nameof(values));
+        }
+
+        VariableName = variableName;
+        Values = values;
+    }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether the test should run if the value of the variable matches any
+    /// of the supplied values. If <c>False</c>, the test runs only if the value does not match any of the
+    /// supplied values. Default is <c>True</c>.
+    /// </summary>
+    public bool RunOnMatch { get; set; } = true;
+
+    /// <summary>
+    /// Gets the name of the environment variable.
+    /// </summary>
+    public string VariableName { get; }
+
+    /// <summary>
+    /// Gets the value(s) of the environment variable to match for the condition.
+    /// </summary>
+    public string[] Values { get; }
+
+    /// <summary>
+    /// Gets a value indicating whether the condition is met for the configured environment variable and values.
+    /// </summary>
+    public bool IsMet
+    {
+        get
+        {
+            _currentValue ??= Environment.GetEnvironmentVariable(VariableName);
+            var hasMatched = Values.Any(value => string.Equals(value, _currentValue, StringComparison.OrdinalIgnoreCase));
+
+            return RunOnMatch ? hasMatched : !hasMatched;
+        }
+    }
+
+    /// <summary>
+    /// Gets a value indicating the reason the test was skipped.
+    /// </summary>
+    public string SkipReason
+    {
+        get
+        {
+            var value = _currentValue ?? "(null)";
+
+            return $"Test skipped on environment variable with name '{VariableName}' and value '{value}' " +
+                $"for the '{nameof(RunOnMatch)}' value of '{RunOnMatch}'.";
+        }
+    }
+}