diff --git a/source/Ldap.Integration.Tests/TestHelpers/FakeUpdateableUserStore.cs b/source/Ldap.Integration.Tests/TestHelpers/FakeUpdateableUserStore.cs
index 2dbf184..c715320 100644
--- a/source/Ldap.Integration.Tests/TestHelpers/FakeUpdateableUserStore.cs
+++ b/source/Ldap.Integration.Tests/TestHelpers/FakeUpdateableUserStore.cs
@@ -2,22 +2,21 @@
 using System.Collections.Generic;
 using System.Threading;
 using Octopus.Data;
-using Octopus.Data.Model;
 using Octopus.Data.Model.User;
 using Octopus.Data.Storage.User;
 using Octopus.Server.Extensibility.Authentication.HostServices;
-using Octopus.Server.Extensibility.Authentication.Ldap.Configuration;
+using Octopus.Server.MessageContracts.Features.Users;
 
 namespace Ldap.Integration.Tests.TestHelpers
 {
     internal class FakeUpdateableUserStore : IUpdateableUserStore
     {
-        public IUser AddIdentity(string userId, Identity identity, CancellationToken cancellationToken)
+        public IUser AddIdentity(UserId userId, Identity identity, CancellationToken cancellationToken)
         {
             throw new NotImplementedException();
         }
 
-        public void ClearSecurityGroupIds(string provider, string userId)
+        public void ClearSecurityGroupIds(string provider, UserId userId)
         {
             throw new NotImplementedException();
         }
@@ -28,12 +27,12 @@ public IResult<IUser> Create(string username, string displayName, string emailAd
             return Result<IUser>.Success(new FakeUser(username, emailAddress, displayName, identities));
         }
 
-        public void DisableUser(string userId)
+        public void DisableUser(UserId userId)
         {
             throw new NotImplementedException();
         }
 
-        public void EnableUser(string userId)
+        public void EnableUser(UserId userId)
         {
             throw new NotImplementedException();
         }
@@ -43,7 +42,7 @@ public IUser[] GetByEmailAddress(string emailAddress)
             throw new NotImplementedException();
         }
 
-        public IUser GetById(string userId)
+        public IUser GetById(UserId userId)
         {
             throw new NotImplementedException();
         }
@@ -64,12 +63,12 @@ public IUser GetByUsername(string username)
             throw new NotImplementedException();
         }
 
-        public void SetSecurityGroupIds(string provider, string userId, IEnumerable<string> ids, DateTimeOffset updated)
+        public void SetSecurityGroupIds(string provider, UserId userId, IEnumerable<string> ids, DateTimeOffset updated)
         {
             throw new NotImplementedException();
         }
 
-        public IUser UpdateIdentity(string userId, Identity identity, CancellationToken cancellationToken)
+        public IUser UpdateIdentity(UserId userId, Identity identity, CancellationToken cancellationToken)
         {
             throw new NotImplementedException();
         }
diff --git a/source/Ldap.Integration.Tests/TestHelpers/FakeUser.cs b/source/Ldap.Integration.Tests/TestHelpers/FakeUser.cs
index 6bc4259..3973710 100644
--- a/source/Ldap.Integration.Tests/TestHelpers/FakeUser.cs
+++ b/source/Ldap.Integration.Tests/TestHelpers/FakeUser.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using Octopus.Data.Model.User;
 using Octopus.Server.Extensibility.Authentication.Ldap.Identities;
+using Octopus.Server.MessageContracts.Features.Users;
 
 namespace Ldap.Integration.Tests.TestHelpers
 {
@@ -31,7 +32,7 @@ public FakeUser(string userName, string email, string displayName, IEnumerable<I
 
         public HashSet<Identity> Identities { get; set; }
 
-        public string Id { get; set; }
+        public UserId Id { get; set; }
 
         public SecurityGroups GetSecurityGroups(string identityProviderName)
         {
diff --git a/source/Server/Server.csproj b/source/Server/Server.csproj
index 2fc6981..c36785d 100644
--- a/source/Server/Server.csproj
+++ b/source/Server/Server.csproj
@@ -21,7 +21,7 @@
     <PackageReference Include="Octopus.Configuration" Version="4.0.0" />
     <PackageReference Include="Octopus.Diagnostics" Version="2.1.1" />
     <PackageReference Include="Octopus.Server.Extensibility" Version="14.0.5" />
-    <PackageReference Include="Octopus.Server.Extensibility.Authentication" Version="10.0.3" />
+    <PackageReference Include="Octopus.Server.Extensibility.Authentication" Version="11.0.0" />
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\images\icon.png">