diff --git a/auditlog/models.py b/auditlog/models.py
index b13763a..b207dc0 100644
--- a/auditlog/models.py
+++ b/auditlog/models.py
@@ -126,15 +126,14 @@ class LogEntryManager(models.Manager):
                 kwargs.setdefault("additional_data", get_additional_data())
 
             objects = [smart_str(instance) for instance in changed_queryset]
-            kwargs["changes"] = json.dumps(
-                {
-                    field_name: {
-                        "type": "m2m",
-                        "operation": operation,
-                        "objects": objects,
-                    }
+            kwargs["changes"] = {
+                field_name: {
+                    "type": "m2m",
+                    "operation": operation,
+                    "objects": objects,
                 }
-            )
+            }
+
             kwargs.setdefault("cid", get_cid())
             return self.create(**kwargs)
 
diff --git a/auditlog_tests/tests.py b/auditlog_tests/tests.py
index 55779b1..09aad02 100644
--- a/auditlog_tests/tests.py
+++ b/auditlog_tests/tests.py
@@ -21,6 +21,7 @@ from django.test import RequestFactory, TestCase, override_settings
 from django.urls import reverse
 from django.utils import dateformat, formats
 from django.utils import timezone as django_timezone
+from django.utils.encoding import smart_str
 
 from auditlog.admin import LogEntryAdmin
 from auditlog.cid import get_cid
@@ -400,6 +401,20 @@ class ManyRelatedModelTest(TestCase):
             log_entry.additional_data, {"related_model_id": self.related.id}
         )
 
+    def test_changes(self):
+        self.obj.related.add(self.related)
+        log_entry = self.obj.history.first()
+        self.assertEqual(
+            log_entry.changes,
+            {
+                "related": {
+                    "type": "m2m",
+                    "operation": "add",
+                    "objects": [smart_str(self.related)],
+                }
+            },
+        )
+
 
 class MiddlewareTest(TestCase):
     """