diff --git a/src/MDConcObjectTagRelTypes.php b/src/MDConcObjectTagRelTypes.php
index 2c81847..617fb56 100644
--- a/src/MDConcObjectTagRelTypes.php
+++ b/src/MDConcObjectTagRelTypes.php
@@ -103,6 +103,8 @@ final class MDConcObjectTagRelTypes implements MDImporterConcordanceListInterfac
             return self::RELATION_TYPE_NAMES[trim(strtolower($input))];
         }
 
+        if (is_numeric($input)) return 'tag';
+
         if (isset(self::RELATION_TYPES_MAPPED_TO_EVENTS[strtolower($input)])) {
             throw new MDImporterTagRelationTypeIsEventType("Tag-object relationship type is signifies not tags, but an event component.");
         }