diff --git a/src/Plugin/facets/processor/ListItemProcessor.php b/src/Plugin/facets/processor/ListItemProcessor.php
index 1d2011b..12516c3 100644
--- a/src/Plugin/facets/processor/ListItemProcessor.php
+++ b/src/Plugin/facets/processor/ListItemProcessor.php
@@ -3,6 +3,7 @@
 namespace Drupal\facets\Plugin\facets\processor;
 
 use Drupal\Core\Config\ConfigManagerInterface;
+use Drupal\Core\Entity\EntityFieldManagerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\facets\FacetInterface;
 use Drupal\facets\FacetSource\SearchApiFacetSourceInterface;
@@ -32,12 +33,21 @@ class ListItemProcessor extends ProcessorPluginBase implements BuildProcessorInt
   private $configManager;
 
   /**
+   * The entity field manager.
+   *
+   * @var \Drupal\Core\Entity\EntityFieldManagerInterface
+   */
+  private $entityFieldManager;
+
+  /**
    * {@inheritdoc}
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, ConfigManagerInterface $config_manager) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, ConfigManagerInterface $config_manager, EntityFieldManagerInterface $entity_field_manager) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
 
     $this->configManager = $config_manager;
+
+    $this->entityFieldManager = $entity_field_manager;
   }
 
   /**
@@ -48,7 +58,8 @@ class ListItemProcessor extends ProcessorPluginBase implements BuildProcessorInt
       $configuration,
       $plugin_id,
       $plugin_definition,
-      $container->get('config.manager')
+      $container->get('config.manager'),
+      $container->get('entity_field.manager')
     );
   }
 
@@ -67,8 +78,22 @@ class ListItemProcessor extends ProcessorPluginBase implements BuildProcessorInt
       $entity = str_replace('entity:', '', $field->getDatasourceId());
     }
 
+    // If it's an entity base field, we find it in the field definitions.
+    // We don't have access to the bundle via SearchApiFacetSourceInterface, so
+    // we check the entity's base fields only.
+    $base_fields = $this->entityFieldManager->getFieldDefinitions($entity, '');
+
+    // This only works for configurable fields.
     $config_entity_name = sprintf('field.storage.%s.%s', $entity, $field_identifier);
-    if ($field = $this->configManager->loadConfigEntityByName($config_entity_name)) {
+
+    if (isset($base_fields[$field_identifier])) {
+      $field = $base_fields[$field_identifier];
+    }
+    elseif ($this->configManager->loadConfigEntityByName($config_entity_name) !== NULL) {
+      $field = $this->configManager->loadConfigEntityByName($config_entity_name);
+    }
+
+    if ($field) {
       $function = $field->getSetting('allowed_values_function');
 
       if (empty($function)) {
@@ -87,6 +112,7 @@ class ListItemProcessor extends ProcessorPluginBase implements BuildProcessorInt
         }
       }
     }
+
     return $results;
   }
 
diff --git a/tests/src/Unit/Plugin/processor/LimitItemProcessorTest.php b/tests/src/Unit/Plugin/processor/LimitItemProcessorTest.php
deleted file mode 100644
index a12efea..0000000
--- a/tests/src/Unit/Plugin/processor/LimitItemProcessorTest.php
+++ /dev/null
@@ -1,125 +0,0 @@
-<?php
-
-namespace Drupal\Tests\facets\Unit\Plugin\processor;
-
-use Drupal\facets\Entity\Facet;
-use Drupal\facets\Plugin\facets\processor\ListItemProcessor;
-use Drupal\facets\Result\Result;
-use Drupal\field\Entity\FieldStorageConfig;
-use Drupal\Tests\UnitTestCase;
-use Drupal\Core\Config\ConfigManager;
-
-/**
- * Unit test for processor.
- *
- * @group facets
- */
-class LimitItemProcessorTest extends UnitTestCase {
-
-  /**
-   * The processor to be tested.
-   *
-   * @var \Drupal\facets\processor\BuildProcessorInterface
-   */
-  protected $processor;
-
-  /**
-   * An array containing the results before the processor has ran.
-   *
-   * @var \Drupal\facets\Result\Result[]
-   */
-  protected $originalResults;
-
-  /**
-   * Creates a new processor object for use in the tests.
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    $this->originalResults = [
-      new Result(1, 1, 10),
-      new Result(2, 2, 5),
-      new Result(3, 3, 15),
-    ];
-
-    $config_manager = $this->getMockBuilder(ConfigManager::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-
-    $processor_id = 'list_item';
-    $this->processor = new ListItemProcessor([], $processor_id, [], $config_manager);
-  }
-
-  /**
-   * Tests facet build method.
-   */
-  public function testNoFilter() {
-    $field = $this->getMockBuilder(FieldStorageConfig::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-    $field->expects($this->at(0))
-      ->method('getSetting')
-      ->with('allowed_values_function')
-      ->willReturn('');
-    $field->expects($this->at(1))
-      ->method('getSetting')
-      ->with('allowed_values')
-      ->willReturn([1 => 'llama', 2 => 'badger', 3 => 'kitten']);
-
-    $config_manager = $this->getMockBuilder(ConfigManager::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-    $config_manager->expects($this->any())
-      ->method('loadConfigEntityByName')
-      ->willReturn($field);
-
-    $processor_id = 'list_item';
-    $processor = new ListItemProcessor([], $processor_id, [], $config_manager);
-
-    $facet = new Facet([], 'facet');
-    $facet->setFieldIdentifier('test_facet');
-    $facet->setResults($this->originalResults);
-    $facet->addProcessor([
-      'processor_id' => 'list_item',
-      'weights' => [],
-      'settings' => [],
-    ]);
-    /** @var \Drupal\facets\Result\Result[] $sorted_results */
-    $sorted_results = $processor->build($facet, $this->originalResults);
-
-    $this->assertCount(3, $sorted_results);
-    $this->assertEquals('llama', $sorted_results[0]->getDisplayValue());
-    $this->assertEquals('badger', $sorted_results[1]->getDisplayValue());
-    $this->assertEquals('kitten', $sorted_results[2]->getDisplayValue());
-  }
-
-  /**
-   * Tests configuration.
-   */
-  public function testConfiguration() {
-    $config = $this->processor->defaultConfiguration();
-    $this->assertEquals([], $config);
-  }
-
-  /**
-   * Tests testDescription().
-   */
-  public function testDescription() {
-    $this->assertEquals('', $this->processor->getDescription());
-  }
-
-  /**
-   * Tests isHidden().
-   */
-  public function testIsHidden() {
-    $this->assertEquals(FALSE, $this->processor->isHidden());
-  }
-
-  /**
-   * Tests isLocked().
-   */
-  public function testIsLocked() {
-    $this->assertEquals(FALSE, $this->processor->isLocked());
-  }
-
-}
diff --git a/tests/src/Unit/Plugin/processor/ListItemProcessorTest.php b/tests/src/Unit/Plugin/processor/ListItemProcessorTest.php
new file mode 100644
index 0000000..8462d19
--- /dev/null
+++ b/tests/src/Unit/Plugin/processor/ListItemProcessorTest.php
@@ -0,0 +1,194 @@
+<?php
+
+namespace Drupal\Tests\facets\Unit\Plugin\processor;
+
+use Drupal\facets\Entity\Facet;
+use Drupal\facets\Plugin\facets\processor\ListItemProcessor;
+use Drupal\facets\Result\Result;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\UnitTestCase;
+use Drupal\Core\Config\ConfigManager;
+use Drupal\Core\Entity\EntityFieldManager;
+use Drupal\Core\Field\BaseFieldDefinition;
+
+/**
+ * Unit test for processor.
+ *
+ * @group facets
+ */
+class ListItemProcessorTest extends UnitTestCase {
+
+  /**
+   * The processor to be tested.
+   *
+   * @var \Drupal\facets\processor\BuildProcessorInterface
+   */
+  protected $processor;
+
+  /**
+   * An array containing the results before the processor has ran.
+   *
+   * @var \Drupal\facets\Result\Result[]
+   */
+  protected $results;
+
+  /**
+   * Creates a new processor object for use in the tests.
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->results = [
+      new Result(1, 1, 10),
+      new Result(2, 2, 5),
+      new Result(3, 3, 15),
+    ];
+
+    $config_manager = $this->getMockBuilder(ConfigManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $entity_field_manager = $this->getMockBuilder(EntityFieldManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $processor_id = 'list_item';
+    $this->processor = new ListItemProcessor([], $processor_id, [], $config_manager, $entity_field_manager);
+  }
+
+  /**
+   * Tests facet build with field.module field.
+   */
+  public function testFacetFieldmoduleBuild() {
+    $module_field = $this->getMockBuilder(FieldStorageConfig::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+    $module_field->expects($this->at(0))
+      ->method('getSetting')
+      ->with('allowed_values_function')
+      ->willReturn('');
+    $module_field->expects($this->at(1))
+      ->method('getSetting')
+      ->with('allowed_values')
+      ->willReturn([
+        1 => 'llama',
+        2 => 'badger',
+        3 => 'kitten',
+      ]);
+
+    $config_manager = $this->getMockBuilder(ConfigManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+    $config_manager->expects($this->any())
+      ->method('loadConfigEntityByName')
+      ->willReturn($module_field);
+
+    $entity_field_manager = $this->getMockBuilder(EntityFieldManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $processor_id = 'list_item';
+    $processor = new ListItemProcessor([], $processor_id, [], $config_manager, $entity_field_manager);
+
+    // Config entity field facet.
+    $module_field_facet = new Facet([], 'facet');
+    $module_field_facet->setFieldIdentifier('test_facet');
+    $module_field_facet->setResults($this->results);
+    $module_field_facet->addProcessor([
+      'processor_id' => 'list_item',
+      'weights' => [],
+      'settings' => [],
+    ]);
+    /** @var \Drupal\facets\Result\Result[] $module_field_facet- */
+    $module_field_results = $processor->build($module_field_facet, $this->results);
+
+    $this->assertCount(3, $module_field_results);
+    $this->assertEquals('llama', $module_field_results[0]->getDisplayValue());
+    $this->assertEquals('badger', $module_field_results[1]->getDisplayValue());
+    $this->assertEquals('kitten', $module_field_results[2]->getDisplayValue());
+  }
+
+  /**
+   * Tests facet build with base props.
+   */
+  public function testFacetBasepropBuild() {
+    $config_manager = $this->getMockBuilder(ConfigManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $base_field = $this->getMockBuilder(BaseFieldDefinition::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+    $base_field->expects($this->any())
+      ->method('getSetting')
+      ->willReturnMap([
+        ['allowed_values_function', ''],
+        ['allowed_values', [
+          1 => 'blue whale',
+          2 => 'lynx',
+          3 => 'dog-wolf-lion',
+        ]],
+      ]);
+
+    $entity_field_manager = $this->getMockBuilder(EntityFieldManager::class)
+      ->disableOriginalConstructor()
+      ->getMock();
+    $entity_field_manager->expects($this->any())
+      ->method('getFieldDefinitions')
+      ->with('node', '')
+      ->willReturn([
+        'test_facet_baseprop' => $base_field,
+      ]);
+
+    $processor_id = 'list_item';
+    $processor = new ListItemProcessor([], $processor_id, [], $config_manager, $entity_field_manager);
+
+    // Base prop facet.
+    $base_prop_facet = new Facet([], 'facet');
+    $base_prop_facet->setFieldIdentifier('test_facet_baseprop');
+    $base_prop_facet->setResults($this->results);
+    $base_prop_facet->addProcessor([
+      'processor_id' => 'list_item',
+      'weights' => [],
+      'settings' => [],
+    ]);
+
+    /** @var \Drupal\facets\Result\Result[] $base_prop_results */
+    $base_prop_results = $processor->build($base_prop_facet, $this->results);
+
+    $this->assertCount(3, $base_prop_results);
+    $this->assertEquals('blue whale', $base_prop_results[0]->getDisplayValue());
+    $this->assertEquals('lynx', $base_prop_results[1]->getDisplayValue());
+    $this->assertEquals('dog-wolf-lion', $base_prop_results[2]->getDisplayValue());
+  }
+
+  /**
+   * Tests configuration.
+   */
+  public function testConfiguration() {
+    $config = $this->processor->defaultConfiguration();
+    $this->assertEquals([], $config);
+  }
+
+  /**
+   * Tests testDescription().
+   */
+  public function testDescription() {
+    $this->assertEquals('', $this->processor->getDescription());
+  }
+
+  /**
+   * Tests isHidden().
+   */
+  public function testIsHidden() {
+    $this->assertEquals(FALSE, $this->processor->isHidden());
+  }
+
+  /**
+   * Tests isLocked().
+   */
+  public function testIsLocked() {
+    $this->assertEquals(FALSE, $this->processor->isLocked());
+  }
+
+}