diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchPageTextTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchPageTextTest.php
index 771976f..91019e6 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchPageTextTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchPageTextTest.php
@@ -66,7 +66,8 @@ function testSearchText() {
     $limit = \Drupal::config('search.settings')->get('and_or_limit');
     $keys = array();
     for ($i = 0; $i < $limit + 1; $i++) {
-      $keys[] = $this->randomName(3);
+      // Use a key of 4 characters to ensure we never generate 'AND' or 'OR'.
+      $keys[] = $this->randomName(4);
       if ($i % 2 == 0) {
         $keys[] = 'OR';
       }