diff --git a/src/csharp/Grpc.IntegrationTesting/TestCredentials.cs b/src/csharp/Grpc.IntegrationTesting/TestCredentials.cs
index aa54cd38a1d4e1ccc92b5e7120698403301348ff..774563d752fd3573f7ff6686e417eb93a586d32d 100644
--- a/src/csharp/Grpc.IntegrationTesting/TestCredentials.cs
+++ b/src/csharp/Grpc.IntegrationTesting/TestCredentials.cs
@@ -35,6 +35,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Reflection;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Grpc.Core;
@@ -89,7 +90,8 @@ namespace Grpc.IntegrationTesting
 
         private static string GetPath(string relativePath)
         {
-            return Path.Combine(TestContext.CurrentContext.TestDirectory, relativePath);
+            var assemblyDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
+            return Path.Combine(assemblyDir, relativePath);
         }
     }
 }