diff --git a/model_utils/tracker.py b/model_utils/tracker.py
index a18a239..62623fe 100644
--- a/model_utils/tracker.py
+++ b/model_utils/tracker.py
@@ -185,7 +185,7 @@ class FieldInstanceTracker:
                 field_tracker = FileDescriptorTracker(field_obj.field)
                 setattr(self.instance.__class__, field, field_tracker)
             else:
-                field_tracker = DeferredAttributeTracker(field, type(self.instance))
+                field_tracker = DeferredAttributeTracker(field)
                 setattr(self.instance.__class__, field, field_tracker)