diff --git a/tests/test_carry.py b/tests/test_carry.py
index 8293765e58..abdf979569 100644
--- a/tests/test_carry.py
+++ b/tests/test_carry.py
@@ -75,8 +75,8 @@ def commit(self, steps: dict[str, str | None]) -> str:
 
 def record_source(version: int, fields: str) -> str:
     return ("from dataclasses import dataclass\nfrom typing import Annotated, ClassVar\n"
-            "from agent_comms.field_codec import Id128Text\n\n"
-            "class RootId(Id128Text):\n    \"\"\"Another representation of the same spelling.\"\"\"\n\n"
+            "from agent_comms.field_codec import Id128, Id128Text\n\n"
+            "class RootKind(Id128):\n    \"\"\"Another kind written in the same spelling.\"\"\"\n\n"
             f"@dataclass(frozen=True)\nclass Record:\n    version: ClassVar[int] = {version}\n{fields}")
 
 
@@ -90,7 +90,7 @@ def record_source(version: int, fields: str) -> str:
     (PLAIN, 2, PLAIN + "    label: str\n", {}, 1),
     (PLAIN, 2, PLAIN + "    label: str\n", {"carry_record": step_source()}, 0),
     (PLAIN, 1, PLAIN + "    kind: ClassVar[str] = 'x'\n", {}, 0),
-    (SPELLED, 1, "    root: Annotated[str, RootId]\n", {}, 0),
+    (SPELLED, 1, "    root: RootKind\n", {}, 0),
     (PLAIN, 1, SPELLED, {}, 1),
 ])
 def test_a_stored_record_format_change_bumps_its_version_and_ships_a_carry(