diff --git a/django/db/models/__init__.py b/django/db/models/__init__.py
index fa5e8eb77d..2279f71639 100644
--- a/django/db/models/__init__.py
+++ b/django/db/models/__init__.py
@@ -1241,7 +1241,7 @@ class Model(object):
     # Handles related many-to-many object retrieval.
     # Examples: Album.get_song(), Album.get_song_list(), Album.get_song_count()
     def _get_related_many_to_many(self, method_name, rel_class, rel_field, **kwargs):
-        kwargs['%s__%s__exact' % (rel_field.name, rel_class._meta.pk.name)] = getattr(self, rel_class._meta.pk.attname)
+        kwargs['%s__%s__exact' % (rel_field.name, self._meta.pk.name)] = getattr(self, self._meta.pk.attname)
         return getattr(rel_class._default_manager, method_name)(**kwargs)
     
     # Handles setting many-to-many related objects.