diff --git a/python/pydantic_core/core_schema.py b/python/pydantic_core/core_schema.py
index 0fcfe9cab..eff30a15a 100644
--- a/python/pydantic_core/core_schema.py
+++ b/python/pydantic_core/core_schema.py
@@ -149,6 +149,7 @@ def exclude_none(self) -> bool: ...
     @property
     def serialize_as_any(self) -> bool: ...
 
+    @property
     def round_trip(self) -> bool: ...
 
     def mode_is_json(self) -> bool: ...