diff --git a/sdk/identity/Azure.Identity/src/IMsalPublicClientInitializerOptions.cs b/sdk/identity/Azure.Identity/src/IMsalPublicClientInitializerOptions.cs
index fd0d0d4d269..ad6de07f34a 100644
--- a/sdk/identity/Azure.Identity/src/IMsalPublicClientInitializerOptions.cs
+++ b/sdk/identity/Azure.Identity/src/IMsalPublicClientInitializerOptions.cs
@@ -6,11 +6,20 @@
 
 namespace Azure.Identity
 {
+    /// <summary>
+    /// tdb.
+    /// </summary>
     [Friend("Azure.Identity.Broker")]
-    internal interface IMsalPublicClientInitializerOptions
+    public interface IMsalPublicClientInitializerOptions
     {
-        Action<PublicClientApplicationBuilder> BeforeBuildClient { get; }
+        /// <summary>
+        /// tdb.
+        /// </summary>
+        Func<PublicClientApplicationBuilder, PublicClientApplicationBuilder> BeforeBuildClient { get; }
 
+        /// <summary>
+        /// tdb.
+        /// </summary>
         bool UseDefaultBrokerAccount { get; set; }
     }
 }
diff --git a/sdk/identity/Azure.Identity/src/MsalPublicClient.cs b/sdk/identity/Azure.Identity/src/MsalPublicClient.cs
index 37df7f88673..ebdce8f96eb 100644
--- a/sdk/identity/Azure.Identity/src/MsalPublicClient.cs
+++ b/sdk/identity/Azure.Identity/src/MsalPublicClient.cs
@@ -13,7 +13,7 @@ namespace Azure.Identity
 {
     internal class MsalPublicClient : MsalClientBase<IPublicClientApplication>
     {
-        private Action<PublicClientApplicationBuilder> _beforeBuildClient;
+        private Func<PublicClientApplicationBuilder, PublicClientApplicationBuilder> _beforeBuildClient;
         internal string RedirectUrl { get; }
 
         protected MsalPublicClient()
@@ -60,7 +60,7 @@ protected virtual ValueTask<IPublicClientApplication> CreateClientCoreAsync(bool
 
             if (_beforeBuildClient != null)
             {
-                _beforeBuildClient(pubAppBuilder);
+                pubAppBuilder = _beforeBuildClient(pubAppBuilder);
             }
 
             if (DisableInstanceDiscovery)
diff --git a/sdk/identity/Azure.Identity/tests/InteractiveBrowserCredentialTests.cs b/sdk/identity/Azure.Identity/tests/InteractiveBrowserCredentialTests.cs
index b176e9cd1b1..c35ea778d2f 100644
--- a/sdk/identity/Azure.Identity/tests/InteractiveBrowserCredentialTests.cs
+++ b/sdk/identity/Azure.Identity/tests/InteractiveBrowserCredentialTests.cs
@@ -268,9 +268,9 @@ public async Task UsesTenantIdHint([Values(null, TenantIdHint)] string tenantId,
 
         public class ExtendedInteractiveBrowserCredentialOptions : InteractiveBrowserCredentialOptions, IMsalPublicClientInitializerOptions
         {
-            private Action<PublicClientApplicationBuilder> _beforeBuildClient;
+            private Func<PublicClientApplicationBuilder, PublicClientApplicationBuilder> _beforeBuildClient;
 
-            public ExtendedInteractiveBrowserCredentialOptions(Action<PublicClientApplicationBuilder> beforeBuildClient)
+            public ExtendedInteractiveBrowserCredentialOptions(Func<PublicClientApplicationBuilder, PublicClientApplicationBuilder> beforeBuildClient)
             {
                 _beforeBuildClient = beforeBuildClient;
             }
@@ -279,7 +279,7 @@ public ExtendedInteractiveBrowserCredentialOptions(Action<PublicClientApplicatio
 
             public bool UseDefaultBrokerAccount { get; set; }
 
-            Action<PublicClientApplicationBuilder> IMsalPublicClientInitializerOptions.BeforeBuildClient { get { return _beforeBuildClient; } }
+            Func<PublicClientApplicationBuilder, PublicClientApplicationBuilder> IMsalPublicClientInitializerOptions.BeforeBuildClient { get { return _beforeBuildClient; } }
         }
 
         [Test]
@@ -294,6 +294,7 @@ public async Task InvokesBeforeBuildClientOnExtendedOptions()
                 Assert.NotNull(builder);
                 beforeBuildClientInvoked = true;
                 cancelSource.Cancel();
+                return builder;
             }
             );