diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index d55c1e0741..b545a5ed3b 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -3179,6 +3179,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
 
     def create_book_entry(self, mi, cover=None, add_duplicates=True,
             force_id=None):
+        if mi.tags:
+            mi.tags = list(mi.tags)
         self._add_newbook_tag(mi)
         if not add_duplicates and self.has_book(mi):
             return None