diff --git a/src/NodaWikidataFetcher.php b/src/NodaWikidataFetcher.php
index 5fc270c..94e847c 100644
--- a/src/NodaWikidataFetcher.php
+++ b/src/NodaWikidataFetcher.php
@@ -1102,8 +1102,8 @@ final class NodaWikidataFetcher {
         $currentPlaceResult->close();
         unset($currentPlaceResult);
 
-        if (isset($data['claims']['P1566'])) $geonames_id = $data['claims']['P1566'][0]['mainsnak']['datavalue']['value'];
-        if (isset($data['claims']['P1667'])) $tgn_id = $data['claims']['P1667'][0]['mainsnak']['datavalue']['value'];
+        if (isset($data['claims']['P1566'])) $geonames_id = filter_var($data['claims']['P1566'][0]['mainsnak']['datavalue']['value'], FILTER_VALIDATE_INT);
+        if (isset($data['claims']['P1667'])) $tgn_id = filter_var($data['claims']['P1667'][0]['mainsnak']['datavalue']['value'], FILTER_VALIDATE_INT);
 
         $nodaLinks = [
             "wikidata" => $wikidata_id,