diff --git a/apps/backoffice/src/app/features/user-management/UserManagementPage.tsx b/apps/backoffice/src/app/features/user-management/UserManagementPage.tsx
index 6a96bba84..a3e3d8f90 100644
--- a/apps/backoffice/src/app/features/user-management/UserManagementPage.tsx
+++ b/apps/backoffice/src/app/features/user-management/UserManagementPage.tsx
@@ -99,7 +99,11 @@ const UM_CONFIG: DesignConfig = {
 
 const UM_RUNTIME = {
   basename: '/um',
-  apiUrl: import.meta.env.VITE_BASE_API_URL,
+  // Keep the embedded IAM module on the same API as the backoffice client.
+  // When VITE_BASE_API_URL is absent locally, passing undefined makes iamui
+  // fall back to its remote development server, where the local JWT is
+  // rejected and the module redirects to its login page.
+  apiUrl: import.meta.env.VITE_BASE_API_URL ?? 'http://localhost:3000/api',
 };
 
 const buttonStyle: React.CSSProperties = {