diff --git a/templates/partials/app-topbar.phtml b/templates/partials/app-topbar.phtml
index f012621..328b118 100644
--- a/templates/partials/app-topbar.phtml
+++ b/templates/partials/app-topbar.phtml
@@ -37,7 +37,7 @@ $allowUserTheme = allowUserTheme();
     <div class="app-topbar-center" aria-hidden="true"></div>
     <ul class="app-topbar-right">
       <?php if ($canSwitchTenant): ?>
-        <li class="app-topbar-tenant-slot" data-tooltip="<?php e(t('Tenant')); ?>" data-tooltip-pos="bottom">
+        <li class="app-topbar-tenant-slot" data-tenant-switcher data-tooltip="<?php e(t('Tenant')); ?>" data-tooltip-pos="bottom">
           <details class="dropdown app-topbar-tenant-menu">
             <summary class="app-topbar-tenant-chip" aria-label="<?php e(t('Switch tenant')); ?>" title="<?php e($tenantLabel); ?>">
               <span class="app-topbar-tenant-name"><?php e($tenantLabel); ?></span>
diff --git a/web/js/components/app-tenant-switcher.js b/web/js/components/app-tenant-switcher.js
index 7f90a18..416e5af 100644
--- a/web/js/components/app-tenant-switcher.js
+++ b/web/js/components/app-tenant-switcher.js
@@ -1,5 +1,8 @@
 import { showAsyncFlash } from './app-async-flash.js';
-import { warnOnce } from '../core/app-dom.js';
+import { optionalEl, warnOnce } from '../core/app-dom.js';
+
+const SWITCHER_ROOT_SELECTOR = '[data-tenant-switcher]';
+const TENANT_LINK_SELECTOR = '[data-switch-tenant]';
 
 const setPending = (link, pending) => {
   link.style.pointerEvents = pending ? 'none' : '';
@@ -66,9 +69,15 @@ const switchTenant = async (link) => {
 };
 
 const initTenantSwitcher = () => {
-  const tenantLinks = document.querySelectorAll('[data-switch-tenant]');
+  const switcherRoot = optionalEl(SWITCHER_ROOT_SELECTOR);
+  if (!switcherRoot) {
+    // Single-tenant users do not render a switcher; this is expected.
+    return;
+  }
+
+  const tenantLinks = Array.from(switcherRoot.querySelectorAll(TENANT_LINK_SELECTOR));
   if (!tenantLinks.length) {
-    warnOnce('UI_EL_MISSING', 'Missing tenant switch links', { module: 'tenant-switcher' });
+    warnOnce('UI_EL_MISSING', 'Tenant switcher root exists but contains no switch links', { module: 'tenant-switcher' });
     return;
   }