diff --git a/src/Adapter/MSTestAdapter.PlatformServices/Utilities/AppDomainUtilities.cs b/src/Adapter/MSTestAdapter.PlatformServices/Utilities/AppDomainUtilities.cs
index a5751f5031..f3d0b2afbc 100644
--- a/src/Adapter/MSTestAdapter.PlatformServices/Utilities/AppDomainUtilities.cs
+++ b/src/Adapter/MSTestAdapter.PlatformServices/Utilities/AppDomainUtilities.cs
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 #if NETFRAMEWORK
@@ -6,7 +6,6 @@
 using Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter;
 using Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Deployment;
 using Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Interface;
-using Microsoft.VisualStudio.TestPlatform.ObjectModel;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Utilities;
@@ -18,9 +17,22 @@ internal static class AppDomainUtilities
 {
     private const string ObjectModelVersionBuiltAgainst = "11.0.0.0";
 
+    private const string ObjectModelAssemblyName = "Microsoft.VisualStudio.TestPlatform.ObjectModel";
+
     private static readonly Version DefaultVersion = new();
     private static readonly Version Version45 = new("4.5");
 
+    /// <summary>
+    /// Resolves the loaded VSTest object-model assembly by simple name, so this AppDomain-wiring code does not
+    /// need a compile-time reference to it. By the time these methods run (test source host setup during
+    /// discovery/execution) the adapter has already loaded the object model into the current (parent) domain,
+    /// so its identity — including any binding redirect in effect — matches what a direct type reference resolved to.
+    /// </summary>
+    /// <returns>The object-model assembly.</returns>
+    private static Assembly GetObjectModelAssembly()
+        => AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault(a => string.Equals(a.GetName().Name, ObjectModelAssemblyName, StringComparison.Ordinal))
+            ?? Assembly.Load(ObjectModelAssemblyName);
+
     /// <summary>
     /// Gets or sets the Xml Utilities instance.
     /// </summary>
@@ -90,7 +102,7 @@ internal static string GetTargetFrameworkVersionString(string testSourcePath)
 
             var resolutionPaths = new List<string>
                 {
-                    Path.GetDirectoryName(typeof(TestCase).Assembly.Location),
+                    Path.GetDirectoryName(GetObjectModelAssembly().Location),
                     Path.GetDirectoryName(testSourcePath),
                 };
 
@@ -157,10 +169,10 @@ internal static void SetConfigurationFile(AppDomainSetup appDomainSetup, string?
         try
         {
             // Add redirection of the built 11.0 Object Model assembly to the current version if that is not 11.0
-            string currentVersionOfObjectModel = typeof(TestCase).Assembly.GetName().Version.ToString();
+            string currentVersionOfObjectModel = GetObjectModelAssembly().GetName().Version.ToString();
             if (!string.Equals(currentVersionOfObjectModel, ObjectModelVersionBuiltAgainst, StringComparison.Ordinal))
             {
-                AssemblyName assemblyName = typeof(TestCase).Assembly.GetName();
+                AssemblyName assemblyName = GetObjectModelAssembly().GetName();
                 byte[] configurationBytes =
                     XmlUtilities.AddAssemblyRedirection(
                         testSourceConfigFile,