diff --git a/src/ORM/FieldType/DBForeignKey.php b/src/ORM/FieldType/DBForeignKey.php
index 109eb3846..1c4532204 100644
--- a/src/ORM/FieldType/DBForeignKey.php
+++ b/src/ORM/FieldType/DBForeignKey.php
@@ -72,6 +72,9 @@ class DBForeignKey extends DBInt
             if ($hasOneSingleton instanceof Image) {
                 $field->setAllowedFileCategories('image/supported');
             }
+            if ($field->hasMethod('setAllowedMaxFileNumber')) {
+                $field->setAllowedMaxFileNumber(1);
+            }
             return $field;
         }