diff --git a/backend/pashub_fetcher/core_files.py b/backend/pashub_fetcher/core_files.py
index 4b1023d2..75981cb1 100644
--- a/backend/pashub_fetcher/core_files.py
+++ b/backend/pashub_fetcher/core_files.py
@@ -71,6 +71,8 @@ def core_file_for(
         return CoreFiles.IMPROVEMENT_OPTION_EVALUATION
     if CoreFiles.MEDIUM_TERM_IMPROVEMENT_PLAN.value in filename:
         return CoreFiles.MEDIUM_TERM_IMPROVEMENT_PLAN
+    if evidence_category is None and "-OSM-" in filename and "DR-N-A" in filename:
+        return CoreFiles.RETROFIT_DESIGN_DOC
     raise NotImplementedError