diff --git a/src/guidellm/utils/encoding.py b/src/guidellm/utils/encoding.py
index 5e001c8ec..bcc296b56 100644
--- a/src/guidellm/utils/encoding.py
+++ b/src/guidellm/utils/encoding.py
@@ -431,7 +431,7 @@ def to_dict_pydantic(self, item: Any) -> Any:
             "*PYD*": True,
             "typ": item.__class__.__name__,
             "mod": item.__class__.__module__,
-            "dat": item.model_dump(mode="python"),
+            "dat": item.model_dump(mode="python", exclude_computed_fields=True),
         }
 
     def from_dict_pydantic(self, item: dict[str, Any]) -> Any:
@@ -572,7 +572,9 @@ def to_sequence_pydantic(self, obj: BaseModel) -> str | bytes:
         """
         class_name: str = obj.__class__.__name__
         class_module: str = obj.__class__.__module__
-        json_data = obj.__pydantic_serializer__.to_json(obj)
+        json_data = obj.__pydantic_serializer__.to_json(
+            obj, exclude_computed_fields=True
+        )
 
         return class_name.encode() + b"|" + class_module.encode() + b"|" + json_data
 
diff --git a/tests/unit/utils/test_encoding.py b/tests/unit/utils/test_encoding.py
index 1cdf3689f..b5a7059a5 100644
--- a/tests/unit/utils/test_encoding.py
+++ b/tests/unit/utils/test_encoding.py
@@ -201,7 +201,6 @@ def test_encode_decode_pydantic(self, valid_instances, obj: Any):
         else:
             assert decoded == obj
 
-    @pytest.mark.xfail(reason="old and broken", run=False)
     @pytest.mark.smoke
     @pytest.mark.parametrize(
         "obj",