diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index b12ea4b6c9..08aa439007 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -1276,9 +1276,9 @@ class OPF(object):  # {{{
                      'isbn', 'tags', 'category', 'comments', 'book_producer',
                      'pubdate', 'user_categories', 'author_link_map'):
             val = getattr(mi, attr, None)
-            is_null = val is None or val in ((), [], (None, None), {})
+            is_null = val is None or val in ((), [], (None, None), {}) or (attr == 'rating' and val < 0.1)
             if is_null:
-                if apply_null and attr in {'series', 'tags', 'isbn', 'comments', 'publisher'}:
+                if apply_null and attr in {'series', 'tags', 'isbn', 'comments', 'publisher', 'rating'}:
                     setattr(self, attr, ([] if attr == 'tags' else None))
             else:
                 setattr(self, attr, val)