diff --git a/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs b/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
index 0f0ff0c2cce1e2..b4d9be2a52744d 100644
--- a/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
+++ b/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
@@ -6,6 +6,9 @@
 using System.Linq;
 using System.Net;
 using System.Runtime.InteropServices;
+#if NET7_0_OR_GREATER
+using System.Runtime.InteropServices.Marshalling;
+#endif
 using System.Security.Cryptography;
 using System.Security.Principal;
 using System.Threading.Tasks;
@@ -118,12 +121,15 @@ private void CreateUser()
         [return: MarshalAs(UnmanagedType.Bool)]
         private static partial bool LogonUser(string userName, string domain, string password, int logonType, int logonProvider, out SafeAccessTokenHandle safeAccessTokenHandle);
 
-        [DllImport("netapi32.dll", SetLastError = true)]
-        internal static extern uint NetUserAdd([MarshalAs(UnmanagedType.LPWStr)] string servername, uint level, ref USER_INFO_1 buf, out uint parm_err);
+        [LibraryImport("netapi32.dll", SetLastError = true)]
+        internal static partial uint NetUserAdd([MarshalAs(UnmanagedType.LPWStr)] string servername, uint level, ref USER_INFO_1 buf, out uint parm_err);
 
         [LibraryImport("netapi32.dll")]
         internal static partial uint NetUserDel([MarshalAs(UnmanagedType.LPWStr)] string servername, [MarshalAs(UnmanagedType.LPWStr)] string username);
 
+#if NET7_0_OR_GREATER
+        [NativeMarshalling(typeof(USER_INFO_1.Marshaller))]
+#endif
         [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
         internal struct USER_INFO_1
         {
@@ -135,6 +141,65 @@ internal struct USER_INFO_1
             public string usri1_comment;
             public uint usri1_flags;
             public string usri1_script_path;
+
+#if NET7_0_OR_GREATER
+            [CustomMarshaller(typeof(USER_INFO_1), MarshalMode.Default, typeof(Marshaller))]
+            public static class Marshaller
+            {
+                public static USER_INFO_1Native ConvertToUnmanaged(USER_INFO_1 managed) => new(managed);
+                public static USER_INFO_1 ConvertToManaged(USER_INFO_1Native native) => native.ToManaged();
+                public static void Free(USER_INFO_1Native native) => native.FreeNative();
+
+                [StructLayout(LayoutKind.Sequential)]
+                public struct USER_INFO_1Native
+                {
+                    private IntPtr usri1_name;
+                    private IntPtr usri1_password;
+                    private uint usri1_password_age;
+                    private uint usri1_priv;
+                    private IntPtr usri1_home_dir;
+                    private IntPtr usri1_comment;
+                    private uint usri1_flags;
+                    private IntPtr usri1_script_path;
+
+                    public USER_INFO_1Native(USER_INFO_1 managed)
+                    {
+                        usri1_name = Marshal.StringToCoTaskMemUni(managed.usri1_name);
+                        usri1_password = Marshal.StringToCoTaskMemUni(managed.usri1_password);
+                        usri1_password_age = managed.usri1_password_age;
+                        usri1_priv = managed.usri1_priv;
+                        usri1_home_dir = Marshal.StringToCoTaskMemUni(managed.usri1_home_dir);
+                        usri1_comment = Marshal.StringToCoTaskMemUni(managed.usri1_comment);
+                        usri1_flags = managed.usri1_flags;
+                        usri1_script_path = Marshal.StringToCoTaskMemUni(managed.usri1_script_path);
+                    }
+
+                    public USER_INFO_1 ToManaged()
+                    {
+                        return new USER_INFO_1
+                        {
+                            usri1_name = Marshal.PtrToStringUni(usri1_name),
+                            usri1_password = Marshal.PtrToStringUni(usri1_password),
+                            usri1_password_age = usri1_password_age,
+                            usri1_priv = usri1_priv,
+                            usri1_home_dir = Marshal.PtrToStringUni(usri1_home_dir),
+                            usri1_comment = Marshal.PtrToStringUni(usri1_comment),
+                            usri1_flags = usri1_flags,
+                            usri1_script_path = Marshal.PtrToStringUni(usri1_script_path)
+                        };
+                    }
+
+                    public void FreeNative()
+                    {
+                        Marshal.FreeCoTaskMem(usri1_name);
+                        Marshal.FreeCoTaskMem(usri1_password);
+                        Marshal.FreeCoTaskMem(usri1_home_dir);
+                        Marshal.FreeCoTaskMem(usri1_comment);
+                        Marshal.FreeCoTaskMem(usri1_script_path);
+                    }
+                }
+            }
+#endif
         }
 
         public void Dispose()