diff --git a/modules/identity/src/Volo.Abp.Identity.Domain/Volo/Abp/Identity/IIdentityUserRepository.cs b/modules/identity/src/Volo.Abp.Identity.Domain/Volo/Abp/Identity/IIdentityUserRepository.cs
index 59d6087d06..9729d03129 100644
--- a/modules/identity/src/Volo.Abp.Identity.Domain/Volo/Abp/Identity/IIdentityUserRepository.cs
+++ b/modules/identity/src/Volo.Abp.Identity.Domain/Volo/Abp/Identity/IIdentityUserRepository.cs
@@ -104,8 +104,8 @@ public interface IIdentityUserRepository : IBasicRepository<IdentityUser, Guid>
     );
 
     Task<IdentityUser> FindByTenantIdAndUserNameAsync(
-        Guid tenantId,
         [NotNull] string userName,
+        Guid? tenantId,
         bool includeDetails = true,
         CancellationToken cancellationToken = default
     );
diff --git a/modules/identity/src/Volo.Abp.Identity.EntityFrameworkCore/Volo/Abp/Identity/EntityFrameworkCore/EfCoreIdentityUserRepository.cs b/modules/identity/src/Volo.Abp.Identity.EntityFrameworkCore/Volo/Abp/Identity/EntityFrameworkCore/EfCoreIdentityUserRepository.cs
index 1b0cdc825b..ab9cc892d6 100644
--- a/modules/identity/src/Volo.Abp.Identity.EntityFrameworkCore/Volo/Abp/Identity/EntityFrameworkCore/EfCoreIdentityUserRepository.cs
+++ b/modules/identity/src/Volo.Abp.Identity.EntityFrameworkCore/Volo/Abp/Identity/EntityFrameworkCore/EfCoreIdentityUserRepository.cs
@@ -304,8 +304,8 @@ public class EfCoreIdentityUserRepository : EfCoreRepository<IIdentityDbContext,
     }
 
     public virtual async Task<IdentityUser> FindByTenantIdAndUserNameAsync(
-        Guid tenantId, 
         [NotNull] string userName,
+        Guid? tenantId, 
         bool includeDetails = true,
         CancellationToken cancellationToken = default)
     {
diff --git a/modules/identity/src/Volo.Abp.Identity.MongoDB/Volo/Abp/Identity/MongoDB/MongoIdentityUserRepository.cs b/modules/identity/src/Volo.Abp.Identity.MongoDB/Volo/Abp/Identity/MongoDB/MongoIdentityUserRepository.cs
index 01c92489f6..71d0d2eb53 100644
--- a/modules/identity/src/Volo.Abp.Identity.MongoDB/Volo/Abp/Identity/MongoDB/MongoIdentityUserRepository.cs
+++ b/modules/identity/src/Volo.Abp.Identity.MongoDB/Volo/Abp/Identity/MongoDB/MongoIdentityUserRepository.cs
@@ -272,8 +272,8 @@ public class MongoIdentityUserRepository : MongoDbRepository<IAbpIdentityMongoDb
     }
 
     public virtual async Task<IdentityUser> FindByTenantIdAndUserNameAsync(
-        Guid tenantId, 
         [NotNull] string userName, 
+        Guid? tenantId, 
         bool includeDetails = true, 
         CancellationToken cancellationToken = default)
     {