X-Git-Url: https://git.mdrn.pl/redakcja.git/blobdiff_plain/2bde30d633af49f2d3d40305e30df68c04dc0786..14f2c24a604e36cad62ba9f6f8d71bf500f8e35a:/src/isbn/models.py

diff --git a/src/isbn/models.py b/src/isbn/models.py
index 14e973d8..43d01bfc 100644
--- a/src/isbn/models.py
+++ b/src/isbn/models.py
@@ -142,7 +142,7 @@ class Isbn(models.Model):
                     add_note = False
                     if isbn.book is None:
                         isbn.book = catalogue_book
-                    elif isbn.book is not catalogue_book:
+                    elif isbn.book != catalogue_book:
                         add_note = True
                     if not isbn.form:
                         isbn.form = form