diff --git a/core/modules/toolbar/tests/src/Unit/PageCache/AllowToolbarPathTest.php b/core/modules/toolbar/tests/src/Unit/PageCache/AllowToolbarPathTest.php
index aef4ec8..f1223be 100644
--- a/core/modules/toolbar/tests/src/Unit/PageCache/AllowToolbarPathTest.php
+++ b/core/modules/toolbar/tests/src/Unit/PageCache/AllowToolbarPathTest.php
@@ -56,6 +56,7 @@ public function providerTestAllowToolbarPath() {
       [RequestPolicyInterface::ALLOW, '/de/toolbar/subtrees/abcd'],
       [RequestPolicyInterface::ALLOW, '/en-us/toolbar/subtrees/xyz'],
       [RequestPolicyInterface::ALLOW, '/en-us/toolbar/subtrees/xyz/de'],
+      [RequestPolicyInterface::ALLOW, '/a/b/c/toolbar/subtrees/xyz/de'],
       [RequestPolicyInterface::ALLOW, '/toolbar/subtrees/some-hash'],
       [RequestPolicyInterface::ALLOW, '/toolbar/subtrees/some-hash/en'],
     ];