diff --git a/packages/core/src/middleware/koa-spa-session-guard.test.ts b/packages/core/src/middleware/koa-spa-session-guard.test.ts
index 164b1e103..9a68c290e 100644
--- a/packages/core/src/middleware/koa-spa-session-guard.test.ts
+++ b/packages/core/src/middleware/koa-spa-session-guard.test.ts
@@ -1,7 +1,8 @@
 import { createMockUtils } from '@logto/shared/esm';
 import Provider from 'oidc-provider';
+import Sinon from 'sinon';
 
-import { UserApps } from '#src/env-set/index.js';
+import { EnvSet, UserApps } from '#src/env-set/index.js';
 import { MockQueries } from '#src/test-utils/tenant.js';
 import { createContextWithRouteParameters } from '#src/utils/test-utils.js';
 
@@ -100,4 +101,18 @@ describe('koaSpaSessionGuard', () => {
     await koaSpaSessionGuard(provider, queries)(ctx, next);
     expect(ctx.redirect).toBeCalledWith('https://foo.bar');
   });
+
+  it(`should redirect to current hostname if isDomainBasedMultiTenancy`, async () => {
+    const stub = Sinon.stub(EnvSet, 'values').value({
+      ...EnvSet.values,
+      isDomainBasedMultiTenancy: true,
+    });
+    interactionDetails.mockRejectedValue(new Error('session not found'));
+    const ctx = createContextWithRouteParameters({
+      url: '/sign-in/foo',
+    });
+    await koaSpaSessionGuard(provider, queries)(ctx, next);
+    expect(ctx.redirect).toBeCalledWith('https://test.com/unknown-session');
+    stub.restore();
+  });
 });
diff --git a/packages/core/src/middleware/koa-spa-session-guard.ts b/packages/core/src/middleware/koa-spa-session-guard.ts
index 0d0177bb5..a76c60752 100644
--- a/packages/core/src/middleware/koa-spa-session-guard.ts
+++ b/packages/core/src/middleware/koa-spa-session-guard.ts
@@ -55,9 +55,15 @@ export default function koaSpaSessionGuard<
           throw new RequestError({ code: 'session.not_found', status: 404 });
         }
 
-        ctx.redirect(
-          appendPath(getTenantEndpoint(tenantId, EnvSet.values), sessionNotFoundPath).href
-        );
+        const tenantEndpoint = getTenantEndpoint(tenantId, EnvSet.values);
+
+        if (EnvSet.values.isDomainBasedMultiTenancy) {
+          // Replace to current hostname (if custom domain is used)
+          // eslint-disable-next-line @silverhand/fp/no-mutation
+          tenantEndpoint.hostname = ctx.request.hostname;
+        }
+
+        ctx.redirect(appendPath(tenantEndpoint, sessionNotFoundPath).href);
 
         return;
       }