Refs #24227 -- Replaced M2M isinstance checks by field.many_to_many

Thanks Markus Holtermann, Collin Anderson and Tim Graham for the reviews.

1 files changed, 1 insertions, 3 deletions

diff --git a/django/forms/models.py b/django/forms/models.py
index 4422882315..067f601493 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -79,8 +79,6 @@ def model_to_dict(instance, fields=None, exclude=None):
     fields will be excluded from the returned dict, even if they are listed in
     the ``fields`` argument.
     """
-    # avoid a circular import
-    from django.db.models.fields.related import ManyToManyField
     opts = instance._meta
     data = {}
     for f in chain(opts.concrete_fields, opts.virtual_fields, opts.many_to_many):
@@ -90,7 +88,7 @@ def model_to_dict(instance, fields=None, exclude=None):
             continue
         if exclude and f.name in exclude:
             continue
-        if isinstance(f, ManyToManyField):
+        if f.many_to_many:
             # If the object doesn't have a primary key yet, just use an empty
             # list for its m2m fields. Calling f.value_from_object will raise
             # an exception.