diff --git a/src/Bundle/ChillMainBundle/Service/Import/AddressReferenceFromBano.php b/src/Bundle/ChillMainBundle/Service/Import/AddressReferenceFromBano.php
index ade89c6ff..fd17f2cd2 100644
--- a/src/Bundle/ChillMainBundle/Service/Import/AddressReferenceFromBano.php
+++ b/src/Bundle/ChillMainBundle/Service/Import/AddressReferenceFromBano.php
@@ -58,7 +58,7 @@ class AddressReferenceFromBano
         foreach ($stmt as $record) {
             $this->baseImporter->importAddress(
                 $record['refId'],
-                substr($record['refId'], 0, 5), // extract insee from reference
+                substr((string) $record['refId'], 0, 5), // extract insee from reference
                 $record['postcode'],
                 $record['street'],
                 $record['streetNumber'],