diff --git a/typo3/sysext/indexed_search/Classes/Indexer.php b/typo3/sysext/indexed_search/Classes/Indexer.php
index 478a44fb2c5a12d108ab95eb6bda6a517850e13a..172e9ecd25e8351e8036d171b4ec34a87cffc4a2 100644
--- a/typo3/sysext/indexed_search/Classes/Indexer.php
+++ b/typo3/sysext/indexed_search/Classes/Indexer.php
@@ -364,7 +364,7 @@ class Indexer
         // Set to defaults
         $this->conf['freeIndexUid'] = 0;
         $this->conf['freeIndexSetId'] = 0;
-        $this->conf['page_cache_reg1'] = '';
+        $this->conf['page_cache_reg1'] = 0;
         // Root line uids
         $this->conf['rootline_uids'] = $uidRL;
         // Configuration of behavior: