diff --git a/backend/app/domain/test_entity.py b/backend/app/domain/test_entity.py
index 29eea1d..514bdda 100644
--- a/backend/app/domain/test_entity.py
+++ b/backend/app/domain/test_entity.py
@@ -166,7 +166,8 @@ class TestEntity:
 
         Raises :class:`InvalidStateTransition` when the move is illegal.
         """
-        resolved = target if isinstance(target, TestState) else TestState(str(target))
+        value = target.value if hasattr(target, "value") else str(target)
+        resolved = target if isinstance(target, TestState) else TestState(value)
         return self._transition(resolved)
 
     def _transition(self, target: TestState) -> str: