diff --git a/src/MDRequirementsSet.php b/src/MDRequirementsSet.php
index 81de6db..2d0fb7e 100644
--- a/src/MDRequirementsSet.php
+++ b/src/MDRequirementsSet.php
@@ -47,4 +47,6 @@ final class MDRequirementsSet {
     const MIMETYPES_CATALOGUE_WORK_IMAGE = ['image/jpeg', 'image/jpg'];
     const MIMETYPES_CATALOGUE_OBJECT_SUMMARY_IMAGE = ['image/jpeg', 'image/jpg'];
 
+    const EXTENSIONS_THREE_D_ZIP = ['obj', 'mtl', 'jpg', 'jpeg', 'png'];
+
 }