diff --git a/src/agent_comms/todos.py b/src/agent_comms/todos.py
index c6876fbc1f..3e155a81a1 100644
--- a/src/agent_comms/todos.py
+++ b/src/agent_comms/todos.py
@@ -49,6 +49,7 @@
 )
 from .goals import CheckedCommit, OrderCheck, ProblemGoalOrder
 from .launch_runtime import BuildIdentity, UnrecordedBuildIdentity
+from .maintenance_barrier import MaintenanceBarrier
 from .order_story import ProblemStory, StoryEvent, StoryLine, StorySource
 from .plan_phases import OrderPhase, UnplannedPhase
 from .recorded_time import EventTime, RecordedEventTime, UnrecordedEventTime
@@ -328,7 +329,7 @@ def belongs_to(self, todo: Todo) -> bool:
         return (todo.id in self.problems
                 or any(identity in self.orders for identity in todo.held_order_ids))
 
-    def merged_commits(self) -> Iterator[str]:
+    def merged_commits(self, since: float) -> Iterator[str]:
         return iter(())
 
     async def delivery_merges(self, delivery: CommitDelivery,
@@ -345,8 +346,9 @@ class MergedPullRequest(PullRequest):
     merge: str
     merged_at: float
 
-    def merged_commits(self) -> Iterator[str]:
-        yield self.merge
+    def merged_commits(self, since: float) -> Iterator[str]:
+        if self.merged_at >= since:
+            yield self.merge
 
     async def delivery_merges(self, delivery: CommitDelivery,
                               check: OrderCheck) -> tuple[DeliveryMerge, ...]:
@@ -930,7 +932,7 @@ class MergedProgress(FoundProgress):
     @classmethod
     def found(cls, source: ProgressSource) -> Iterator[Self]:
         return (cls(sha) for pr in source.requests("merged")
-                for sha in pr.merged_commits())
+                for sha in pr.merged_commits(source.since))
 
     @property
     def state(self) -> str:
diff --git a/tests/test_order_progress.py b/tests/test_order_progress.py
index 4cddca923c..e3d1eb8c1d 100644
--- a/tests/test_order_progress.py
+++ b/tests/test_order_progress.py
@@ -119,6 +119,30 @@ def test_unfinished_check_keeps_other_overdue_orders_visible(
         todo.order.check.result.require(run)
 
 
+@pytest.mark.parametrize('merged_at', (200.0, 201.0))
+def test_reissued_order_rejects_earlier_merge_and_accepts_its_own(
+        checkout, commander, merged_at):
+    first, unit = checkout
+    sha = commit(unit)
+    earlier = MergedPullRequest(7, 'fix/p1', sha, merge=sha, merged_at=150.0,
+                               updated_at=150.0, orders=(first.order.id,))
+    comms, caller = commander
+    following = replace(first.order, id='resent-P1', at=RecordedEventTime(200.0))
+    CommsOrderTool(owner='worker', order=OrderGoalAction(
+        problem='P1', order=following, request='request', deadline=RecordedEventTime(3000),
+        commander='lead', expected_revision=first.revision,
+        assigner=comms.registry.require('lead').incarnation)).apply(comms, caller)
+    current = comms.goals.todos.get('P1')
+    assert current.prior_orders == (first.order,)
+    assert not isinstance(read((current, unit), Listed(merged=(earlier,))), MergedProgress)
+    assert comms.goals.todos.get('P1') == current and current.state.open
+    assert tuple(earlier.merged_commits(200.0)) == ()
+    later = replace(earlier, number=8, merged_at=merged_at, updated_at=merged_at,
+                    orders=(following.id,))
+    assert tuple(later.merged_commits(200.0)) == (sha,)
+    assert read((current, unit), Listed(merged=(earlier, later))) == MergedProgress(sha)
+
+
 def test_no_commit_since_the_order_is_explicit(checkout):
     progress = read(checkout)
     assert progress == NoCommitProgress()