diff --git a/dotnet/src/webdriver/BiDi/Modules/Network/AuthCredentials.cs b/dotnet/src/webdriver/BiDi/Modules/Network/AuthCredentials.cs
index 9178e32af2efd..f3bd0343a557b 100644
--- a/dotnet/src/webdriver/BiDi/Modules/Network/AuthCredentials.cs
+++ b/dotnet/src/webdriver/BiDi/Modules/Network/AuthCredentials.cs
@@ -21,11 +21,10 @@
 
 namespace OpenQA.Selenium.BiDi.Modules.Network;
 
-[JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
-[JsonDerivedType(typeof(Basic), "password")]
-public abstract record AuthCredentials
+public record AuthCredentials(string Username, string Password)
 {
-    public record Basic(string Username, string Password) : AuthCredentials;
+    [JsonInclude]
+    internal string Type { get; } = "password";
 }
 
 
diff --git a/dotnet/test/common/BiDi/Network/NetworkTest.cs b/dotnet/test/common/BiDi/Network/NetworkTest.cs
index 9a6c457e69e0e..2773d539dbb37 100644
--- a/dotnet/test/common/BiDi/Network/NetworkTest.cs
+++ b/dotnet/test/common/BiDi/Network/NetworkTest.cs
@@ -163,7 +163,7 @@ public async Task CanContinueWithAuthCredentials()
         await using var intercept = await bidi.Network.InterceptAuthAsync(async e =>
         {
             //TODO Seems it would be better to have method which takes abstract options
-            await e.Request.Request.ContinueWithAuthAsync(new AuthCredentials.Basic("test", "test"));
+            await e.Request.Request.ContinueWithAuthAsync(new AuthCredentials("test", "test"));
         });
 
         await context.NavigateAsync(UrlBuilder.WhereIs("basicAuth"), new() { Wait = ReadinessState.Complete });