diff --git a/includes/datasource_multiple.inc b/includes/datasource_multiple.inc
index 8156cc1..2c3f900 100644
--- a/includes/datasource_multiple.inc
+++ b/includes/datasource_multiple.inc
@@ -10,8 +10,6 @@
  */
 class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataSourceController {
 
-  const TYPE_SEPARATOR = '/';
-
   /**
    * {@inheritdoc}
    */
@@ -33,7 +31,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
   public function loadItems(array $ids) {
     $ids_by_type = array();
     foreach ($ids as $id) {
-      list($type, $type_id) = explode(self::TYPE_SEPARATOR, $id);
+      list($type, $type_id) = explode('/', $id);
       $ids_by_type[$type][$type_id] = $id;
     }
 
@@ -143,7 +141,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
 
           // Select all entity ids.
           $query = db_select($table, 't');
-          $query->addExpression("CONCAT(:prefix, t.$id_field)", 'item_id', array(':prefix' => $type . self::TYPE_SEPARATOR));
+          $query->addExpression("CONCAT(:prefix, t.$id_field)", 'item_id', array(':prefix' => $type . '/'));
           $query->addExpression(':index_id', 'index_id', array(':index_id' => $index->id));
           $query->addExpression('1', 'changed');
 
@@ -165,7 +163,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
           $ids = !empty($result[$type]) ? array_keys($result[$type]) : array();
           if ($ids) {
             foreach ($ids as $i => $id) {
-              $ids[$i] = $type . self::TYPE_SEPARATOR . $id;
+              $ids[$i] = $type . '/' . $id;
             }
             $this->trackItemInsert($ids, array($index), TRUE);
           }
@@ -201,7 +199,7 @@ class SearchApiCombinedEntityDataSourceController extends SearchApiAbstractDataS
       if (!$skip_type_check) {
         $types = $this->getEntityTypes($index);
         foreach ($ids as $id) {
-          list($type) = explode(self::TYPE_SEPARATOR, $id);
+          list($type) = explode('/', $id);
           if (!isset($types[$type])) {
             unset($ids[$id]);
           }
diff --git a/search_api.module b/search_api.module
index ad8b1ab..c510a0d 100644
--- a/search_api.module
+++ b/search_api.module
@@ -858,7 +858,7 @@ function search_api_entity_insert($entity, $type) {
   list($id) = entity_extract_ids($type, $entity);
   if (isset($id)) {
     search_api_track_item_insert($type, array($id));
-    $combined_id = $type . SearchApiCombinedEntityDataSourceController::TYPE_SEPARATOR . $id;
+    $combined_id = $type . '/' . $id;
     search_api_track_item_insert('multiple', array($combined_id));
   }
 }
@@ -892,7 +892,7 @@ function search_api_entity_update($entity, $type) {
 
   if (isset($id)) {
     search_api_track_item_change($type, array($id));
-    $combined_id = $type . SearchApiCombinedEntityDataSourceController::TYPE_SEPARATOR . $id;
+    $combined_id = $type . '/' . $id;
     search_api_track_item_change('multiple', array($combined_id));
   }
 }
@@ -915,7 +915,7 @@ function search_api_entity_delete($entity, $type) {
   list($id) = entity_extract_ids($type, $entity);
   if (isset($id)) {
     search_api_track_item_delete($type, array($id));
-    $combined_id = $type . SearchApiCombinedEntityDataSourceController::TYPE_SEPARATOR . $id;
+    $combined_id = $type . '/' . $id;
     search_api_track_item_delete('multiple', array($combined_id));
   }
 }