diff --git a/includes/callback_bundle_filter.inc b/includes/callback_bundle_filter.inc
index 6a36e6e..50a9dc9 100644
--- a/includes/callback_bundle_filter.inc
+++ b/includes/callback_bundle_filter.inc
@@ -34,26 +34,19 @@ class SearchApiAlterBundleFilter extends SearchApiAbstractAlterCallback {
       return;
     }
 
-    $entity_type = $this->isMultiEntityIndex() ? NULL : $this->index->getEntityType();
-    // If the index contains multiple entity type, $info will contain the infos
-    // of all types, otherwise it's just the info of the relevant type.
-    $info = entity_get_info($entity_type);
-    $bundle_prop = $this->isMultiEntityIndex() ? NULL : $info['entity keys']['bundle'];
+    if ($this->isMultiEntityIndex()) {
+      $bundle_prop = 'item_bundle';
+    }
+    else {
+      $info = entity_get_info($this->index->getEntityType());
+      $bundle_prop = $info['entity keys']['bundle'];
+    }
 
     $bundles = array_flip($this->options['bundles']);
     $default = (bool) $this->options['default'];
 
     foreach ($items as $id => $item) {
-      if ($entity_type) {
-        $bundle = $item->$bundle_prop;
-      }
-      else {
-        if (!isset($info[$item->_type]['entity keys']['bundle'])) {
-          continue;
-        }
-        $bundle = $item->_type . ':' . $item->{$item->_type}->{$info[$item->_type]['entity keys']['bundle']};
-      }
-      if (isset($bundles[$bundle]) == $default) {
+      if (isset($bundles[$item->$bundle_prop]) == $default) {
         unset($items[$id]);
       }
     }
diff --git a/includes/datasource_multiple.inc b/includes/datasource_multiple.inc
index 2c3f900..13b8881 100644
--- a/includes/datasource_multiple.inc
+++ b/includes/datasource_multiple.inc
@@ -20,7 +20,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
    */
   public function getIdFieldInfo() {
     return array(
-      'key' => '_id',
+      'key' => 'item_id',
       'type' => 'string',
     );
   }
@@ -31,19 +31,30 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
   public function loadItems(array $ids) {
     $ids_by_type = array();
     foreach ($ids as $id) {
-      list($type, $type_id) = explode('/', $id);
-      $ids_by_type[$type][$type_id] = $id;
+      list($type, $entity_id) = explode('/', $id);
+      $ids_by_type[$type][$entity_id] = $id;
     }
 
     $items = array();
     foreach ($ids_by_type as $type => $type_ids) {
-      foreach (entity_load($type, array_keys($type_ids)) as $type_id => $item) {
-        $id = $type_ids[$type_id];
-        $item = (object) array($type => $item);
-        $item->_id = $id;
-        $item->_type = $type;
+      foreach (entity_load($type, array_keys($type_ids)) as $entity_id => $entity) {
+        $id = $type_ids[$entity_id];
+        $item = (object) array($type => $entity);
+        $item->item_id = $id;
+        $item->item_type = $type;
+        $item->item_entity_id = $entity_id;
+        $item->item_bundle = NULL;
+        try {
+          list(, , $bundle) = entity_extract_ids($type, $entity);
+          $item->item_bundle = $bundle ? "$type:$bundle" : NULL;
+        }
+        catch (EntityMalformedException $e) {
+          // Will probably make problems at some other place, but for extracting
+          // the bundle it is really not critical enough to fail on – just
+          // ignore this exception.
+        }
         $items[$id] = $item;
-        unset($type_ids[$type_id]);
+        unset($type_ids[$entity_id]);
       }
       if ($type_ids) {
         search_api_track_item_delete($type, array_keys($type_ids));
@@ -58,17 +69,28 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
    */
   protected function getPropertyInfo() {
     $info = array(
-      '_id' => array(
+      'item_id' => array(
         'label' => t('ID'),
-        'description' => t('The datasource-specific ID of the item.'),
-        'type' => 'text',
+        'description' => t('The combined ID of the item, containing both entity type and entity ID.'),
+        'type' => 'token',
       ),
-      '_type' => array(
+      'item_type' => array(
         'label' => t('Entity type'),
         'description' => t('The entity type of the item.'),
         'type' => 'token',
         'options list' => 'search_api_entity_type_options_list',
       ),
+      'item_entity_id' => array(
+        'label' => t('Entity ID'),
+        'description' => t('The entity ID of the item.'),
+        'type' => 'token',
+      ),
+      'item_bundle' => array(
+        'label' => t('Bundle'),
+        'description' => t('The bundle of the item, if applicable.'),
+        'type' => 'token',
+        'options list' => 'search_api_combined_bundle_options_list',
+      ),
     );
 
     foreach ($this->getSelectedEntityTypeOptions() as $type => $label) {
@@ -86,14 +108,14 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
    * {@inheritdoc}
    */
   public function getItemId($item) {
-    return isset($item->_id) ? $item->_id : NULL;
+    return isset($item->item_id) ? $item->item_id : NULL;
   }
 
   /**
    * {@inheritdoc}
    */
   public function getItemLabel($item) {
-    $label = entity_label($item->_type, $item->{$item->_type});
+    $label = entity_label($item->item_type, $item->{$item->item_type});
     return $label ? $label : NULL;
   }
 
@@ -101,7 +123,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
    * {@inheritdoc}
    */
   public function getItemUrl($item) {
-    if ($item->_type == 'file') {
+    if ($item->item_type == 'file') {
       return array(
         'path' => file_create_url($item->file->uri),
         'options' => array(
@@ -110,7 +132,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
         ),
       );
     }
-    $url = entity_uri($item->_type, $item->{$item->_type});
+    $url = entity_uri($item->item_type, $item->{$item->item_type});
     return $url ? $url : NULL;
   }
 
diff --git a/search_api.module b/search_api.module
index 6d90a1a..08919e9 100644
--- a/search_api.module
+++ b/search_api.module
@@ -2862,6 +2862,28 @@ function search_api_entity_type_options_list() {
 }
 
 /**
+ * Options list callback for entity type bundles.
+ *
+ * Will include all bundles for all entity types which specify entity property
+ * information, in a format combining both entity type and bundle.
+ *
+ * @return string[]
+ *   An array of bundle identifiers mapped to their human-readable names.
+ */
+function search_api_combined_bundle_options_list() {
+  $types = array();
+  foreach (array_keys(entity_get_property_info()) as $type) {
+    $info = entity_get_info($type);
+    if (!empty($info['bundles'])) {
+      foreach ($info['bundles'] as $bundle => $bundle_info) {
+        $types["$type:$bundle"] = $bundle_info['label'];
+      }
+    }
+  }
+  return $types;
+}
+
+/**
  * Shutdown function which indexes all queued items, if any.
  */
 function _search_api_index_queued_items() {