--- /dev/null
+<?php
+
+/**
+ * @file
+ * Test fixture.
+ */
+
+use Drupal\Core\Database\Database;
+
+$connection = Database::getConnection();
+
+// Enable Layout Builder on an existing entity view display.
+$display = $connection->select('config')
+ ->fields('config', ['data'])
+ ->condition('collection', '')
+ ->condition('name', 'core.entity_view_display.node.article.default')
+ ->execute()
+ ->fetchField();
+$display = unserialize($display);
+$display['third_party_settings']['layout_builder']['enabled'] = TRUE;
+$connection->update('config')
+ ->fields([
+ 'data' => serialize($display),
+ 'collection' => '',
+ 'name' => 'core.entity_view_display.node.article.default',
+ ])
+ ->condition('collection', '')
+ ->condition('name', 'core.entity_view_display.node.article.default')
+ ->execute();