diff --git a/src/nglui/parser/base.py b/src/nglui/parser/base.py
index b951824..6b04a8c 100644
--- a/src/nglui/parser/base.py
+++ b/src/nglui/parser/base.py
@@ -366,7 +366,7 @@ def _generic_annotations(
             tag_list = [anno.get("tagIds", []) for anno in annos]
         else:
             tag_list = [
-                [ii for ii, val in enumerate(anno["props"]) if val == 1]
+                [ii for ii, val in enumerate(anno.get("props", [])) if val == 1]
                 for anno in annos
             ]
         out.append(tag_list)