diff --git a/src/calibre/ebooks/metadata/opf3.py b/src/calibre/ebooks/metadata/opf3.py
index 47ecbba785..7ff7233aff 100644
--- a/src/calibre/ebooks/metadata/opf3.py
+++ b/src/calibre/ebooks/metadata/opf3.py
@@ -1052,7 +1052,7 @@ def apply_metadata(root, mi, cover_prefix='', cover_data=None, apply_null=False,
         set_publisher(root, prefixes, refines, mi.publisher)
     if ok('tags'):
         set_tags(root, prefixes, refines, mi.tags)
-    if ok('rating') and mi.rating > 0.1:
+    if ok('rating') and mi.rating is not None and mi.rating > 0.1:
         set_rating(root, prefixes, refines, mi.rating)
     if ok('series'):
         set_series(root, prefixes, refines, mi.series, mi.series_index or 1)