diff --git a/contrib/search_api_facetapi/search_api_facetapi.module b/contrib/search_api_facetapi/search_api_facetapi.module
index b452734..feff684 100644
--- a/contrib/search_api_facetapi/search_api_facetapi.module
+++ b/contrib/search_api_facetapi/search_api_facetapi.module
@@ -65,6 +65,9 @@ function search_api_facetapi_facetapi_searcher_info() {
         'supports facet mincount' => TRUE,
         'include default facets' => FALSE,
       );
+      if (($entity_type = $index->getEntityType()) && $entity_type !== $index->item_type) {
+        $info[$searcher_name]['types'][] = $entity_type;
+      }
     }
   }
   return $info;
@@ -80,7 +83,7 @@ function search_api_facetapi_facetapi_facet_info(array $searcher_info) {
     if (!empty($index->options['fields'])) {
       $wrapper = $index->entityWrapper();
       $bundle_key = NULL;
-      if (($entity_info = entity_get_info($index->item_type)) && !empty($entity_info['bundle keys']['bundle'])) {
+      if ($index->getEntityType() && ($entity_info = entity_get_info($index->getEntityType())) && !empty($entity_info['bundle keys']['bundle'])) {
         $bundle_key = $entity_info['bundle keys']['bundle'];
       }
 
@@ -144,7 +147,7 @@ function search_api_facetapi_facetapi_facet_info(array $searcher_info) {
         if ($bundle_key) {
           if ($key === $bundle_key) {
             // Set entity type this field contains bundle information for.
-            $facet_info[$key]['field api bundles'][] = $index->item_type;
+            $facet_info[$key]['field api bundles'][] = $index->getEntityType();
           }
           else {
             // Add "bundle" as possible dependency plugin.
diff --git a/contrib/search_api_views/includes/query.inc b/contrib/search_api_views/includes/query.inc
index b5c8fa6..f9d6f90 100644
--- a/contrib/search_api_views/includes/query.inc
+++ b/contrib/search_api_views/includes/query.inc
@@ -388,11 +388,11 @@ class SearchApiViewsQuery extends views_plugin_query {
    * query backend.
    */
   public function get_result_wrappers($results, $relationship = NULL, $field = NULL) {
-    $is_entity = (boolean) entity_get_info($this->index->item_type);
+    $entity_type = $this->index->getEntityType();
     $wrappers = array();
     $load_entities = array();
     foreach ($results as $row_index => $row) {
-      if ($is_entity && isset($row->entity)) {
+      if ($entity_type && isset($row->entity)) {
         // If this entity isn't load, register it for pre-loading.
         if (!is_object($row->entity)) {
           $load_entities[$row->entity] = $row_index;
@@ -405,14 +405,14 @@ class SearchApiViewsQuery extends views_plugin_query {
     // If the results are entities, we pre-load them to make use of a multiple
     // load. (Otherwise, each result would be loaded individually.)
     if (!empty($load_entities)) {
-      $entities = entity_load($this->index->item_type, array_keys($load_entities));
+      $entities = entity_load($entity_type, array_keys($load_entities));
       foreach ($entities as $entity_id => $entity) {
         $wrappers[$load_entities[$entity_id]] = $this->index->entityWrapper($entity);
       }
     }
 
     // Apply the relationship, if necessary.
-    $type = $this->index->item_type;
+    $type = $entity_type ? $entity_type : $this->index->item_type;
     $selector_suffix = '';
     if ($field && ($pos = strrpos($field, ':'))) {
       $selector_suffix = substr($field, 0, $pos);
diff --git a/contrib/search_api_views/search_api_views.views.inc b/contrib/search_api_views/search_api_views.views.inc
index 3fc2b8f..5d2337c 100644
--- a/contrib/search_api_views/search_api_views.views.inc
+++ b/contrib/search_api_views/search_api_views.views.inc
@@ -20,9 +20,9 @@ function search_api_views_views_data() {
         'help' => t('Use the %name search index for filtering and retrieving data.', array('%name' => $index->name)),
         'query class' => 'search_api_views_query',
       );
-      if (isset($entity_types[$index->item_type])) {
+      if (isset($entity_types[$index->getEntityType()])) {
         $table['table'] += array(
-          'entity type' => $index->item_type,
+          'entity type' => $index->getEntityType(),
           'skip entity load' => TRUE,
         );
       }
diff --git a/includes/callback_add_viewed_entity.inc b/includes/callback_add_viewed_entity.inc
index bd0f8d8..2adcad0 100644
--- a/includes/callback_add_viewed_entity.inc
+++ b/includes/callback_add_viewed_entity.inc
@@ -11,14 +11,16 @@ class SearchApiAlterAddViewedEntity extends SearchApiAbstractAlterCallback {
    * @see SearchApiAlterCallbackInterface::supportsIndex()
    */
   public function supportsIndex(SearchApiIndex $index) {
-    return (bool) entity_get_info($index->item_type);
+    return (bool) $index->getEntityType();
   }
 
   public function configurationForm() {
-    $info = entity_get_info($this->index->item_type);
     $view_modes = array();
-    foreach ($info['view modes'] as $key => $mode) {
-      $view_modes[$key] = $mode['label'];
+    if ($entity_type = $this->index->getEntityType()) {
+      $info = entity_get_info($entity_type);
+      foreach ($info['view modes'] as $key => $mode) {
+        $view_modes[$key] = $mode['label'];
+      }
     }
     $this->options += array('mode' => reset($view_modes));
     if (count($view_modes) > 1) {
@@ -60,7 +62,7 @@ class SearchApiAlterAddViewedEntity extends SearchApiAbstractAlterCallback {
     $original_user = $GLOBALS['user'];
     $GLOBALS['user'] = drupal_anonymous_user();
 
-    $type = $this->index->item_type;
+    $type = $this->index->getEntityType();
     $mode = empty($this->options['mode']) ? 'full' : $this->options['mode'];
     foreach ($items as $id => &$item) {
       // Since we can't really know what happens in entity_view() and render(),
diff --git a/includes/callback_bundle_filter.inc b/includes/callback_bundle_filter.inc
index 4c758c3..e1072b6 100644
--- a/includes/callback_bundle_filter.inc
+++ b/includes/callback_bundle_filter.inc
@@ -7,11 +7,11 @@
 class SearchApiAlterBundleFilter extends SearchApiAbstractAlterCallback {
 
   public function supportsIndex(SearchApiIndex $index) {
-    return ($info = entity_get_info($index->item_type)) && self::hasBundles($info);
+    return $index->getEntityType() && ($info = entity_get_info($index->getEntityType())) && self::hasBundles($info);
   }
 
   public function alterItems(array &$items) {
-    $info = entity_get_info($this->index->item_type);
+    $info = entity_get_info($this->index->getEntityType());
     if (self::hasBundles($info) && isset($this->options['bundles'])) {
       $bundles = array_flip($this->options['bundles']);
       $default = (bool) $this->options['default'];
@@ -25,7 +25,7 @@ class SearchApiAlterBundleFilter extends SearchApiAbstractAlterCallback {
   }
 
   public function configurationForm() {
-    $info = entity_get_info($this->index->item_type);
+    $info = entity_get_info($this->index->getEntityType());
     if (self::hasBundles($info)) {
       $options = array();
       foreach ($info['bundles'] as $bundle => $bundle_info) {
diff --git a/includes/callback_node_access.inc b/includes/callback_node_access.inc
index ce671d7..5acc76c 100644
--- a/includes/callback_node_access.inc
+++ b/includes/callback_node_access.inc
@@ -22,7 +22,7 @@ class SearchApiAlterNodeAccess extends SearchApiAbstractAlterCallback {
    */
   public function supportsIndex(SearchApiIndex $index) {
     // Currently only node access is supported.
-    return $index->item_type === 'node';
+    return $index->getEntityType() === 'node';
   }
 
   /**
diff --git a/includes/callback_node_status.inc b/includes/callback_node_status.inc
index bfe35e2..ee57c38 100644
--- a/includes/callback_node_status.inc
+++ b/includes/callback_node_status.inc
@@ -22,7 +22,7 @@ class SearchApiAlterNodeStatus extends SearchApiAbstractAlterCallback {
    *   TRUE if the callback can run on the given index; FALSE otherwise.
    */
   public function supportsIndex(SearchApiIndex $index) {
-    return $index->item_type === 'node';
+    return $index->getEntityType() === 'node';
   }
 
   /**
diff --git a/includes/datasource.inc b/includes/datasource.inc
index 21a6157..b4ef5f6 100644
--- a/includes/datasource.inc
+++ b/includes/datasource.inc
@@ -237,6 +237,14 @@ interface SearchApiDataSourceControllerInterface {
    */
   public function getIndexStatus(SearchApiIndex $index);
 
+  /**
+   * Get the entity type of items from this datasource.
+   *
+   * @return string|null
+   *   An entity type string if the items provided by this datasource are
+   *   entities; NULL otherwise.
+   */
+  public function getEntityType();
 }
 
 /**
@@ -265,6 +273,15 @@ abstract class SearchApiAbstractDataSourceController implements SearchApiDataSou
   protected $type;
 
   /**
+   * The entity type for this controller instance.
+   *
+   * @var string|null
+   *
+   * @see getEntityType()
+   */
+  protected $entityType = NULL;
+
+  /**
    * The info array for the item type, as specified via
    * hook_search_api_item_type_info().
    *
@@ -314,6 +331,21 @@ abstract class SearchApiAbstractDataSourceController implements SearchApiDataSou
   public function __construct($type) {
     $this->type = $type;
     $this->info = search_api_get_item_type_info($type);
+
+    if (!empty($this->info['entity_type'])) {
+      $this->entityType = $this->info['entity_type'];
+    }
+  }
+
+  /**
+   * Get the entity type of items from this datasource.
+   *
+   * @return string|null
+   *   An entity type string if the items provided by this datasource are
+   *   entities; NULL otherwise.
+   */
+  public function getEntityType() {
+    return $this->entityType;
   }
 
   /**
@@ -333,7 +365,7 @@ abstract class SearchApiAbstractDataSourceController implements SearchApiDataSou
    */
   public function getMetadataWrapper($item = NULL, array $info = array()) {
     $info += $this->getPropertyInfo();
-    return entity_metadata_wrapper($this->type, $item, $info);
+    return entity_metadata_wrapper($this->entityType ? $this->entityType : $this->type, $item, $info);
   }
 
   /**
@@ -689,8 +721,10 @@ abstract class SearchApiAbstractDataSourceController implements SearchApiDataSou
     if ($index->item_type != $this->type) {
       $index_type = search_api_get_item_type_info($index->item_type);
       $index_type = empty($index_type['name']) ? $index->item_type : $index_type['name'];
-      $msg = t('Invalid index @index of type @index_type passed to data source controller for type @this_type.',
-          array('@index' => $index->name, '@index_type' => $index_type, '@this_type' => $this->info['name']));
+      $msg = t(
+        'Invalid index @index of type @index_type passed to data source controller for type @this_type.',
+        array('@index' => $index->name, '@index_type' => $index_type, '@this_type' => $this->info['name'])
+      );
       throw new SearchApiDataSourceException($msg);
     }
   }
diff --git a/includes/datasource_entity.inc b/includes/datasource_entity.inc
index 641a939..6f15ec5 100644
--- a/includes/datasource_entity.inc
+++ b/includes/datasource_entity.inc
@@ -20,8 +20,8 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *     search_api_field_types(). List types ("list<*>") are not allowed.
    */
   public function getIdFieldInfo() {
-    $info = entity_get_info($this->type);
-    $properties = entity_get_property_info($this->type);
+    $info = entity_get_info($this->entityType);
+    $properties = entity_get_property_info($this->entityType);
     if (empty($info['entity keys']['id'])) {
       throw new SearchApiDataSourceException(t("Entity type @type doesn't specify an ID key.", array('@type' => $info['label'])));
     }
@@ -52,7 +52,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *   The loaded items, keyed by ID.
    */
   public function loadItems(array $ids) {
-    $items = entity_load($this->type, $ids);
+    $items = entity_load($this->entityType, $ids);
     // If some items couldn't be loaded, remove them from tracking.
     if (count($items) != count($ids)) {
       $ids = array_flip($ids);
@@ -80,7 +80,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    * @see entity_metadata_wrapper()
    */
   public function getMetadataWrapper($item = NULL, array $info = array()) {
-    return entity_metadata_wrapper($this->type, $item, $info);
+    return entity_metadata_wrapper($this->entityType, $item, $info);
   }
 
   /**
@@ -93,7 +93,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *   Either the unique ID of the item, or NULL if none is available.
    */
   public function getItemId($item) {
-    $id = entity_id($this->type, $item);
+    $id = entity_id($this->entityType, $item);
     return $id ? $id : NULL;
   }
 
@@ -107,7 +107,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *   Either a human-readable label for the item, or NULL if none is available.
    */
   public function getItemLabel($item) {
-    $label = entity_label($this->type, $item);
+    $label = entity_label($this->entityType, $item);
     return $label ? $label : NULL;
   }
 
@@ -123,7 +123,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *   item has no URL of its own.
    */
   public function getItemUrl($item) {
-    if ($this->type == 'file') {
+    if ($this->entityType == 'file') {
       return array(
         'path' => file_create_url($item->uri),
         'options' => array(
@@ -132,7 +132,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
         ),
       );
     }
-    $url = entity_uri($this->type, $item);
+    $url = entity_uri($this->entityType, $item);
     return $url ? $url : NULL;
   }
 
@@ -158,7 +158,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
     // all items again without any key conflicts.
     $this->stopTracking($indexes);
 
-    $entity_info = entity_get_info($this->type);
+    $entity_info = entity_get_info($this->entityType);
 
     if (!empty($entity_info['base table'])) {
       // Use a subselect, which will probably be much faster than entity_load().
@@ -200,7 +200,7 @@ class SearchApiEntityDataSourceController extends SearchApiAbstractDataSourceCon
    *   An array containing all item IDs for this type.
    */
   protected function getAllItemIds() {
-    return array_keys(entity_load($this->type));
+    return array_keys(entity_load($this->entityType));
   }
 
 }
diff --git a/includes/index_entity.inc b/includes/index_entity.inc
index f12bfbd..fdc6673 100644
--- a/includes/index_entity.inc
+++ b/includes/index_entity.inc
@@ -366,6 +366,17 @@ class SearchApiIndex extends Entity {
   }
 
   /**
+   * Get the entity type of items in this index.
+   *
+   * @return string|null
+   *   An entity type string if the items in this index are entities; NULL
+   *   otherwise.
+   */
+  public function getEntityType() {
+    return $this->datasource()->getEntityType();
+  }
+
+  /**
    * Get the server this index lies on.
    *
    * @param $reset
diff --git a/search_api.api.php b/search_api.api.php
index 555688b..d1b8336 100644
--- a/search_api.api.php
+++ b/search_api.api.php
@@ -95,6 +95,9 @@ function hook_search_api_service_info_alter(array &$service_info) {
  *   - datasource controller: A class implementing the
  *     SearchApiDataSourceControllerInterface interface which will be used as
  *     the data source controller for this type.
+ *   - entity_type: (optional) If the type represents entities, the entity type.
+ *     This is used by SearchApiAbstractDataSourceController for determining the
+ *     entity type of items. Other datasource controllers might ignore this.
  *   Other, datasource-specific settings might also be placed here. These should
  *   be specified with the data source controller in question.
  *
@@ -287,7 +290,7 @@ function hook_search_api_index_items_alter(array &$items, SearchApiIndex $index)
  *   An array containing the indexed items' IDs.
  */
 function hook_search_api_items_indexed(SearchApiIndex $index, array $item_ids) {
-  if ($index->item_type == 'node') {
+  if ($index->getEntityType() == 'node') {
     // Flush page cache of the search page.
     cache_clear_all(url('search'), 'cache_page');
   }
@@ -300,8 +303,11 @@ function hook_search_api_items_indexed(SearchApiIndex $index, array $item_ids) {
  *   The SearchApiQueryInterface object representing the search query.
  */
 function hook_search_api_query_alter(SearchApiQueryInterface $query) {
-  $info = entity_get_info($index->item_type);
-  $query->condition($info['entity keys']['id'], 0, '!=');
+  // Exclude entities with ID 0. (Assume the ID field is always indexed.)
+  if ($query->getIndex()->getEntityType()) {
+    $info = entity_get_info($query->getIndex()->getEntityType());
+    $query->condition($info['entity keys']['id'], 0, '!=');
+  }
 }
 
 /**
diff --git a/search_api.module b/search_api.module
index fd77b41..b1ae7e9 100644
--- a/search_api.module
+++ b/search_api.module
@@ -773,6 +773,7 @@ function search_api_search_api_item_type_info() {
       $types[$type] = array(
         'name' => $info['label'],
         'datasource controller' => 'SearchApiEntityDataSourceController',
+        'entity_type' => $type,
       );
     }
   }