diff --git a/src/agent_comms/todos.py b/src/agent_comms/todos.py
index 19c45babcb..678b22a01c 100644
--- a/src/agent_comms/todos.py
+++ b/src/agent_comms/todos.py
@@ -1325,6 +1325,11 @@ class MergedProblemOrder(ProblemOrder):
     def id(self) -> str:
         return self.original.id
 
+    @property
+    def serves(self) -> type[OrderPhase]:
+        """A merge finishes the phase its order served."""
+        return self.original.serves
+
     def require_close(self) -> None:
         pass