diff --git a/deploy/services/drhider.py b/deploy/services/drhider.py
index 50d3ef5..a1ee671 100644
--- a/deploy/services/drhider.py
+++ b/deploy/services/drhider.py
@@ -457,7 +457,7 @@ class TwoPassObfuscator:
             for fname, content in files:
                 zf.writestr(fname, content)
             if mapping_csv:
-                zf.writestr("mapping.csv", mapping_csv.encode('utf-8'))
+                zf.writestr("mapping.csv", '\ufeff'.encode('utf-8') + mapping_csv.encode('utf-8'))
         return buf.getvalue()
 
     def _build_mapping_csv(self) -> str:
diff --git a/site/services/drhider.py b/site/services/drhider.py
index 50d3ef5..a1ee671 100644
--- a/site/services/drhider.py
+++ b/site/services/drhider.py
@@ -457,7 +457,7 @@ class TwoPassObfuscator:
             for fname, content in files:
                 zf.writestr(fname, content)
             if mapping_csv:
-                zf.writestr("mapping.csv", mapping_csv.encode('utf-8'))
+                zf.writestr("mapping.csv", '\ufeff'.encode('utf-8') + mapping_csv.encode('utf-8'))
         return buf.getvalue()
 
     def _build_mapping_csv(self) -> str: