diff --git a/django/db/migrations/autodetector.py b/django/db/migrations/autodetector.py
index 1ef4becaae..8638faaf68 100644
--- a/django/db/migrations/autodetector.py
+++ b/django/db/migrations/autodetector.py
@@ -156,7 +156,7 @@ class MigrationAutodetector(object):
             old_model_state = self.from_state.models[app_label, old_model_name]
             for field_name, field in old_model_state.fields:
                 old_field = self.old_apps.get_model(app_label, old_model_name)._meta.get_field_by_name(field_name)[0]
-                if hasattr(old_field, "rel") and hasattr(old_field.rel, "through") and not old_field.rel.through._meta.auto_created:
+                if hasattr(old_field, "rel") and getattr(old_field.rel, "through", None) and not old_field.rel.through._meta.auto_created:
                     through_key = (
                         old_field.rel.through._meta.app_label,
                         old_field.rel.through._meta.object_name.lower(),