diff --git a/tests/php/ORM/DBReplicaTest.php b/tests/php/ORM/DBReplicaTest.php
index d601e8b6540..85ef95bff15 100644
--- a/tests/php/ORM/DBReplicaTest.php
+++ b/tests/php/ORM/DBReplicaTest.php
@@ -180,10 +180,12 @@ public function testRoutes(string $path, string $expected): void
     {
         // Create a custom rule to test our controller that should default to using a replica
         $rules = Config::inst()->get(Director::class, 'rules');
+        $rules['test/dev'] = TestController::class;
         $rules['test'] = TestController::class;
         // Ensure that routes staring with '$' are at the bottom of the assoc array index and don't override
         // our new 'test' route
         uksort($rules, fn($a, $b) => str_starts_with($a, '$') ? 1 : (str_starts_with($b, '$') ? -1 : 0));
+        Config::modify()->set(Director::class, 'rules', $rules);
         $this->get($path);
         $this->assertSame($expected, $this->getLastConnectionName());
     }