diff --git a/tests/NATS.Client.Core.Tests/ClusterTests.cs b/tests/NATS.Client.Core.Tests/ClusterTests.cs
index 9f647a572..05b3f2cec 100644
--- a/tests/NATS.Client.Core.Tests/ClusterTests.cs
+++ b/tests/NATS.Client.Core.Tests/ClusterTests.cs
@@ -15,9 +15,11 @@ public async Task Seed_urls_on_retry(bool userAuthInUrl)
                 b.WithServerName($"c1n{i}");
                 if (userAuthInUrl)
                 {
-                    b.WithClientUrlAuthentication("user", "pass");
+                    b.AddServerConfig("resources/configs/auth/password.conf");
+                    b.WithClientUrlAuthentication("a", "b");
                 }
-            });
+            },
+            userAuthInUrl);
 
         await using var cluster2 = new NatsCluster(
             new NullOutputHelper(),
@@ -27,9 +29,11 @@ public async Task Seed_urls_on_retry(bool userAuthInUrl)
                 b.WithServerName($"c2n{i}");
                 if (userAuthInUrl)
                 {
-                    b.WithClientUrlAuthentication("user", "pass");
+                    b.AddServerConfig("resources/configs/auth/password.conf");
+                    b.WithClientUrlAuthentication("a", "b");
                 }
-            });
+            },
+            userAuthInUrl);
 
         // Use the first node from each cluster as the seed
         // so that we can confirm seeds are used on retry
diff --git a/tests/NATS.Client.TestUtilities/NatsServer.cs b/tests/NATS.Client.TestUtilities/NatsServer.cs
index dba7e9eab..682a3fa79 100644
--- a/tests/NATS.Client.TestUtilities/NatsServer.cs
+++ b/tests/NATS.Client.TestUtilities/NatsServer.cs
@@ -494,7 +494,7 @@ public class NatsCluster : IAsyncDisposable
 {
     private readonly ITestOutputHelper _outputHelper;
 
-    public NatsCluster(ITestOutputHelper outputHelper, TransportType transportType, Action<int, NatsServerOptsBuilder>? configure = default)
+    public NatsCluster(ITestOutputHelper outputHelper, TransportType transportType, Action<int, NatsServerOptsBuilder>? configure = default, bool useAuthInUrl = false)
     {
         _outputHelper = outputHelper;
 
@@ -546,13 +546,13 @@ public NatsCluster(ITestOutputHelper outputHelper, TransportType transportType,
         }
 
         _outputHelper.WriteLine($"Starting server 1...");
-        Server1 = NatsServer.Start(outputHelper, opts1);
+        Server1 = NatsServer.Start(outputHelper, opts1, useAuthInUrl: useAuthInUrl);
 
         _outputHelper.WriteLine($"Starting server 2...");
-        Server2 = NatsServer.Start(outputHelper, opts2);
+        Server2 = NatsServer.Start(outputHelper, opts2, useAuthInUrl: useAuthInUrl);
 
         _outputHelper.WriteLine($"Starting server 3...");
-        Server3 = NatsServer.Start(outputHelper, opts3);
+        Server3 = NatsServer.Start(outputHelper, opts3, useAuthInUrl: useAuthInUrl);
     }
 
     public NatsServer Server1 { get; }