diff --git a/config/schema/elasticsearch_connector.backend.schema.yml b/config/schema/elasticsearch_connector.backend.schema.yml
index f3c7296..7910945 100644
--- a/config/schema/elasticsearch_connector.backend.schema.yml
+++ b/config/schema/elasticsearch_connector.backend.schema.yml
@@ -1,4 +1,4 @@
-elasticsearch_connector.backend.plugin.elasticsearch:
+plugin.plugin_configuration.search_api_backend.elasticsearch:
   type: mapping
   label: 'Search API Elasticsearch settings'
   mapping:
@@ -9,6 +9,9 @@ elasticsearch_connector.backend.plugin.elasticsearch:
         cluster:
           type: string
           label: 'The cluster that handles the connection'
+    fuzziness:
+      type: string
+      label: 'Fuzziness'
     scheme:
       type: string
       label: 'The HTTP protocol to use for sending queries'
diff --git a/config/schema/elasticsearch_connector.cluster.schema.yml b/config/schema/elasticsearch_connector.cluster.schema.yml
index 8179925..0f88e0b 100644
--- a/config/schema/elasticsearch_connector.cluster.schema.yml
+++ b/config/schema/elasticsearch_connector.cluster.schema.yml
@@ -24,6 +24,39 @@ elasticsearch_connector.cluster.*:
         multiple_nodes_connection:
           type: boolean
           label: 'Multiple Nodes Connection'
+        use_authentication:
+          type: boolean
+          label: 'Use HTTP authentication method to connect to Elasticsearch.'
+        authentication_type:
+          type: string
+          label: 'HTTP authentication type'
+        username:
+          type: string
+          label: 'The username for authentication'
+        password:
+          type: string
+          label: 'The password for authentication'
+        timeout:
+          type: integer
+          label: 'Connection timeout, in seconds'
+        rewrite:
+          type: mapping
+          label: 'Options for altering the index name'
+          mapping:
+            rewrite_index:
+              type: boolean
+              label: 'Whether to alter the index name'
+            index:
+              type: mapping
+              label: 'Index-specific options for rewrite'
+              mapping:
+                prefix:
+                  type: string
+                  label: 'Prefix to use for the final index name'
+                suffix:
+                  type: string
+                  label: 'Suffix to use for the final index name'
+
     locked:
       type: boolean
       label: 'Locked'
diff --git a/tests/src/Kernel/ClusterSchemaTest.php b/tests/src/Kernel/ClusterSchemaTest.php
new file mode 100644
index 0000000..cd1f23d
--- /dev/null
+++ b/tests/src/Kernel/ClusterSchemaTest.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace Drupal\Tests\elasticsearch_connector\Kernel;
+
+use Drupal\Core\Config\Schema\SchemaCheckTrait;
+use Drupal\elasticsearch_connector\Entity\Cluster;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests the cluster schema definition.
+ *
+ * @group elasticsearch_connector
+ */
+class ClusterSchemaTest extends KernelTestBase {
+
+  use SchemaCheckTrait;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = [
+    'elasticsearch_connector',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+
+    $this->cluster = Cluster::create([
+      'cluster_id' => 'test_cluster',
+      'name' => 'Test cluster',
+      'status' => TRUE,
+      'url' => 'http://elasticsearch:9200',
+      'proxy' => '',
+      'options' => [
+        'multiple_nodes_connection' => FALSE,
+        'use_authentication' => TRUE,
+        'authentication_type' => 'Basic',
+        'username' => 'some_username',
+        'password' => 'test1234',
+        'timeout' => 5,
+        'rewrite' => [
+          'rewrite_index' => TRUE,
+          'index' => [
+            'prefix' => '',
+            'suffix' => '',
+          ],
+        ],
+      ],
+      'locked' => FALSE,
+    ]);
+    $this->cluster->save();
+  }
+
+  /**
+   * Tests that the cluster schema definition is valid.
+   */
+  public function testClusterSchema() {
+    $config_name = 'elasticsearch_connector.cluster.test_cluster';
+    $config_data = $this->config($config_name)->get();
+    $config_typed = \Drupal::service('config.typed');
+    $this->assertTrue($this->checkConfigSchema($config_typed, $config_name, $config_data), 'Cluster schema is valid');
+  }
+}