diff --git a/src/Docfx.Build.Engine/XRefMaps/XRefMapDownloader.cs b/src/Docfx.Build.Engine/XRefMaps/XRefMapDownloader.cs
index 24391f3edac..05d10b92deb 100644
--- a/src/Docfx.Build.Engine/XRefMaps/XRefMapDownloader.cs
+++ b/src/Docfx.Build.Engine/XRefMaps/XRefMapDownloader.cs
@@ -125,7 +125,12 @@ protected static async Task<XRefMap> DownloadFromWebAsync(Uri uri)
         var baseUrl = uri.GetLeftPart(UriPartial.Path);
         baseUrl = baseUrl.Substring(0, baseUrl.LastIndexOf('/') + 1);
 
-        using var httpClient = new HttpClient(new HttpClientHandler() { CheckCertificateRevocationList = true });
+        bool.TryParse(Environment.GetEnvironmentVariable("DOCFX_NO_CHECK_CERTIFICATE_REVOCATION_LIST"), out var noCheckCertificateRevocationList);
+        using var httpClient = new HttpClient(new HttpClientHandler()
+        {
+            CheckCertificateRevocationList = !noCheckCertificateRevocationList
+        });
+
         using var stream = await httpClient.GetStreamAsync(uri);
         using var sr = new StreamReader(stream);
         var map = YamlUtility.Deserialize<XRefMap>(sr);
diff --git a/src/Docfx.Build.Engine/XrefClient.cs b/src/Docfx.Build.Engine/XrefClient.cs
deleted file mode 100644
index 817e65c8c64..00000000000
--- a/src/Docfx.Build.Engine/XrefClient.cs
+++ /dev/null
@@ -1,84 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-using System.Net.Http.Headers;
-
-using Docfx.Common;
-using Docfx.Plugins;
-
-namespace Docfx.Build.Engine;
-
-public class XrefClient
-{
-    public static readonly XrefClient Default = new();
-    private static readonly HttpClient _sharedClient =
-        new Func<HttpClient>(() =>
-        {
-            var client = new HttpClient(new HttpClientHandler { CheckCertificateRevocationList = true });
-            client.DefaultRequestHeaders.Accept.Clear();
-            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
-            return client;
-        })();
-    private readonly HttpClient _client;
-    private readonly SemaphoreSlim _semaphore;
-
-    public XrefClient()
-        : this(_sharedClient, null) { }
-
-    public XrefClient(HttpClient client)
-        : this(null, null) { }
-
-    public XrefClient(int maxParallelism)
-        : this(null, new SemaphoreSlim(maxParallelism)) { }
-
-    public XrefClient(SemaphoreSlim semaphore)
-        : this(null, semaphore) { }
-
-    public XrefClient(HttpClient client, int maxParallelism)
-        : this(client, new SemaphoreSlim(maxParallelism)) { }
-
-    public XrefClient(HttpClient client, SemaphoreSlim semaphore)
-    {
-        _client = client ?? _sharedClient;
-        _semaphore = semaphore;
-    }
-
-    public async Task<List<XRefSpec>> ResolveAsync(string url)
-    {
-        if (_semaphore == null)
-        {
-            return await ResolveCoreAsync(url);
-        }
-        await _semaphore.WaitAsync();
-        try
-        {
-            return await ResolveCoreAsync(url);
-        }
-        finally
-        {
-            if (_semaphore != null)
-            {
-                _semaphore.Release();
-            }
-        }
-    }
-
-    private async Task<List<XRefSpec>> ResolveCoreAsync(string url)
-    {
-        using var stream = await _client.GetStreamAsync(url);
-        using var sr = new StreamReader(stream);
-        var xsList = JsonUtility.Deserialize<List<Dictionary<string, object>>>(sr);
-        return xsList.ConvertAll(item =>
-        {
-            var spec = new XRefSpec();
-            foreach (var pair in item)
-            {
-                if (pair.Value is string s)
-                {
-                    spec[pair.Key] = s;
-                }
-            }
-            return spec;
-        });
-    }
-}