diff --git a/features/steps/invariant_model_steps.py b/features/steps/invariant_model_steps.py
index 1f1ed2d6e..b31b4f91f 100644
--- a/features/steps/invariant_model_steps.py
+++ b/features/steps/invariant_model_steps.py
@@ -7,7 +7,6 @@ querying by is_active, and schema validation.
 from __future__ import annotations
 
 import uuid
-from datetime import UTC, datetime
 
 from behave import given, then, when  # type: ignore[import-untyped]
 from behave.runner import Context  # type: ignore[import-untyped]
diff --git a/robot/helper_invariant_model.py b/robot/helper_invariant_model.py
index 5cabe8d58..bbf8627de 100644
--- a/robot/helper_invariant_model.py
+++ b/robot/helper_invariant_model.py
@@ -4,7 +4,6 @@ from __future__ import annotations
 
 import sys
 import uuid
-from datetime import UTC, datetime
 from pathlib import Path
 
 # Ensure src is importable when run from workspace root
diff --git a/src/cleveragents/infrastructure/database/models.py b/src/cleveragents/infrastructure/database/models.py
index ebcd97a6e..7be96e9b9 100644
--- a/src/cleveragents/infrastructure/database/models.py
+++ b/src/cleveragents/infrastructure/database/models.py
@@ -1322,6 +1322,7 @@ class InvariantModel(Base):  # type: ignore[misc]
     Mapped to table ``invariants`` (migration ``m3_001_invariants_table``).
     """
 
+    __allow_unmapped__ = True
     __tablename__ = "invariants"
 
     # PK: ULID (26-char string) — consistent with all other models in the