diff --git a/src/calibre/gui2/dialogs/metadata_bulk.py b/src/calibre/gui2/dialogs/metadata_bulk.py
index 9dbc3dee5e..ef14c95b1d 100644
--- a/src/calibre/gui2/dialogs/metadata_bulk.py
+++ b/src/calibre/gui2/dialogs/metadata_bulk.py
@@ -436,7 +436,7 @@ class MetadataBulkDialog(QDialog, Ui_MetadataBulkDialog):
             elif not fm['is_multiple']:
                 val = [val]
             elif field == 'authors':
-                val = [v.replace(',', '|') for v in val]
+                val = [v.replace('|', ',') for v in val]
         else:
             val = []
         return val
@@ -566,17 +566,11 @@ class MetadataBulkDialog(QDialog, Ui_MetadataBulkDialog):
             dest_val = mi.get(dest, '')
             if dest_val is None:
                 dest_val = []
-            elif isinstance(dest_val, list):
-                if dest == 'authors':
-                    dest_val = [v.replace(',', '|') for v in dest_val]
-            else:
+            elif not isinstance(dest_val, list):
                 dest_val = [dest_val]
         else:
             dest_val = []
 
-        if len(val) > 0:
-            if src == 'authors':
-                val = [v.replace(',', '|') for v in val]
         if dest_mode == 1:
             val.extend(dest_val)
         elif dest_mode == 2: