diff --git a/sentry_sdk/serializer.py b/sentry_sdk/serializer.py
index 4dc4bb5177..df6a9053c1 100644
--- a/sentry_sdk/serializer.py
+++ b/sentry_sdk/serializer.py
@@ -281,6 +281,9 @@ def _serialize_node_impl(
             else:
                 return obj
 
+        elif callable(getattr(obj, "sentry_repr", None)):
+            return obj.sentry_repr()
+
         elif isinstance(obj, datetime):
             return (
                 text_type(format_timestamp(obj))
diff --git a/tests/test_serializer.py b/tests/test_serializer.py
index 35cbdfb96b..503bc14fb2 100644
--- a/tests/test_serializer.py
+++ b/tests/test_serializer.py
@@ -64,3 +64,12 @@ def test_bytes_serialization_repr(message_normalizer):
 def test_serialize_sets(extra_normalizer):
     result = extra_normalizer({1, 2, 3})
     assert result == [1, 2, 3]
+
+
+def test_serialize_custom_mapping(extra_normalizer):
+    class CustomReprDict(dict):
+        def sentry_repr(self):
+            return "custom!"
+
+    result = extra_normalizer(CustomReprDict(one=1, two=2))
+    assert result == "custom!"