diff --git a/modules/identity/test/Volo.Abp.Identity.EntityFrameworkCore.Tests/Volo/Abp/Identity/EntityFrameworkCore/AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule.cs b/modules/identity/test/Volo.Abp.Identity.EntityFrameworkCore.Tests/Volo/Abp/Identity/EntityFrameworkCore/AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule.cs
index eee78bbfd9..640965266a 100644
--- a/modules/identity/test/Volo.Abp.Identity.EntityFrameworkCore.Tests/Volo/Abp/Identity/EntityFrameworkCore/AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule.cs
+++ b/modules/identity/test/Volo.Abp.Identity.EntityFrameworkCore.Tests/Volo/Abp/Identity/EntityFrameworkCore/AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule.cs
@@ -25,10 +25,8 @@ namespace Volo.Abp.Identity.EntityFrameworkCore;
     typeof(AbpEntityFrameworkCoreSqliteModule))]
 public class AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule : AbpModule
 {
-    public static readonly Guid TenantAId =
-        IdentityUserManager_SharedUser_SeparateDatabase_Tests<AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule>.TenantAId;
-    public static readonly Guid TenantBId =
-        IdentityUserManager_SharedUser_SeparateDatabase_Tests<AbpIdentitySharedUserSeparateDbEntityFrameworkCoreTestModule>.TenantBId;
+    public static readonly Guid TenantAId = IdentitySharedUserSeparateDbConstants.TenantAId;
+    public static readonly Guid TenantBId = IdentitySharedUserSeparateDbConstants.TenantBId;
 
     // Per-app keep-alive connections so the in-memory SQLite databases survive for the test's
     // lifetime (without an open connection, shared-cache in-memory databases are discarded).
diff --git a/modules/identity/test/Volo.Abp.Identity.MongoDB.Tests/Volo/Abp/Identity/MongoDB/AbpIdentitySharedUserSeparateDbMongoDbTestModule.cs b/modules/identity/test/Volo.Abp.Identity.MongoDB.Tests/Volo/Abp/Identity/MongoDB/AbpIdentitySharedUserSeparateDbMongoDbTestModule.cs
index 24ae0c4b1e..0b11a09896 100644
--- a/modules/identity/test/Volo.Abp.Identity.MongoDB.Tests/Volo/Abp/Identity/MongoDB/AbpIdentitySharedUserSeparateDbMongoDbTestModule.cs
+++ b/modules/identity/test/Volo.Abp.Identity.MongoDB.Tests/Volo/Abp/Identity/MongoDB/AbpIdentitySharedUserSeparateDbMongoDbTestModule.cs
@@ -13,14 +13,16 @@ namespace Volo.Abp.Identity.MongoDB;
 [DependsOn(typeof(AbpIdentityMongoDbTestModule))]
 public class AbpIdentitySharedUserSeparateDbMongoDbTestModule : AbpModule
 {
-    public static readonly Guid TenantAId = Guid.Parse("11111111-1111-1111-1111-111111111111");
-    public static readonly Guid TenantBId = Guid.Parse("22222222-2222-2222-2222-222222222222");
+    public static readonly Guid TenantAId = IdentitySharedUserSeparateDbConstants.TenantAId;
+    public static readonly Guid TenantBId = IdentitySharedUserSeparateDbConstants.TenantBId;
 
     public override void ConfigureServices(ServiceConfigurationContext context)
     {
-        // Fixed db names so MongoSandbox's embedded mongod does not accumulate one db per test
-        // method. Each test method generates unique email / userName so cross-test data does not
-        // collide on those fields.
+        // Fixed tenant db names so MongoSandbox's embedded mongod does not accumulate one tenant
+        // db per test method. The host/default database is still configured by
+        // AbpIdentityMongoDbTestModule (random per test run), since AbpIdentityTestBaseModule
+        // re-seeds the host admin/role on every AbpApplication initialization. Each test method
+        // generates unique email / userName so cross-test data does not collide.
         var tenantAConnection = MongoDbFixture.GetConnectionString("AbpIdentity_SharedSeparateDb_TenantA");
         var tenantBConnection = MongoDbFixture.GetConnectionString("AbpIdentity_SharedSeparateDb_TenantB");
 
diff --git a/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentitySharedUserSeparateDbConstants.cs b/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentitySharedUserSeparateDbConstants.cs
new file mode 100644
index 0000000000..a2a86ca83e
--- /dev/null
+++ b/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentitySharedUserSeparateDbConstants.cs
@@ -0,0 +1,12 @@
+using System;
+
+namespace Volo.Abp.Identity;
+
+// Single source of truth for the predefined tenant ids used by the shared-user separate-database
+// test suite. Concrete EF/Mongo test modules and the abstract test class both reference these
+// constants directly so the modules don't have to type-couple back into the test class.
+public static class IdentitySharedUserSeparateDbConstants
+{
+    public static readonly Guid TenantAId = Guid.Parse("11111111-1111-1111-1111-111111111111");
+    public static readonly Guid TenantBId = Guid.Parse("22222222-2222-2222-2222-222222222222");
+}
diff --git a/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentityUserManager_SharedUser_SeparateDatabase_Tests.cs b/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentityUserManager_SharedUser_SeparateDatabase_Tests.cs
index ce7128c5d2..a44b13bc6c 100644
--- a/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentityUserManager_SharedUser_SeparateDatabase_Tests.cs
+++ b/modules/identity/test/Volo.Abp.Identity.TestBase/Volo/Abp/Identity/IdentityUserManager_SharedUser_SeparateDatabase_Tests.cs
@@ -22,8 +22,8 @@ namespace Volo.Abp.Identity;
 public abstract class IdentityUserManager_SharedUser_SeparateDatabase_Tests<TStartupModule> : AbpIdentityTestBase<TStartupModule>
     where TStartupModule : IAbpModule
 {
-    public static readonly Guid TenantAId = Guid.Parse("11111111-1111-1111-1111-111111111111");
-    public static readonly Guid TenantBId = Guid.Parse("22222222-2222-2222-2222-222222222222");
+    public static readonly Guid TenantAId = IdentitySharedUserSeparateDbConstants.TenantAId;
+    public static readonly Guid TenantBId = IdentitySharedUserSeparateDbConstants.TenantBId;
 
     protected IdentityUserManager IdentityUserManager { get; }
     protected IIdentityUserRepository IdentityUserRepository { get; }