diff --git a/distributed/scheduler.py b/distributed/scheduler.py
index 69ee585dfb4..cb5318a8231 100644
--- a/distributed/scheduler.py
+++ b/distributed/scheduler.py
@@ -7060,20 +7060,23 @@ def adaptive_target(self, target_duration=None):
             to_close = self.workers_to_close()
             return len(self.workers) - len(to_close)
 
-    def request_acquire_replicas(
-        self, addr: str, keys: Iterable[str], *, stimulus_id: str
-    ) -> None:
+    def request_acquire_replicas(self, addr: str, keys: list, *, stimulus_id: str):
         """Asynchronously ask a worker to acquire a replica of the listed keys from
         other workers. This is a fire-and-forget operation which offers no feedback for
         success or failure, and is intended for housekeeping and not for computation.
         """
-        who_has = {key: {ws.address for ws in self.tasks[key].who_has} for key in keys}
+        who_has = {}
+        for key in keys:
+            ts = self.tasks[key]
+            who_has[key] = {ws.address for ws in ts.who_has}
+
         if self.validate:
             assert all(who_has.values())
 
         self.stream_comms[addr].send(
             {
                 "op": "acquire-replicas",
+                "keys": keys,
                 "who_has": who_has,
                 "stimulus_id": stimulus_id,
             },
diff --git a/distributed/worker.py b/distributed/worker.py
index 9e3ea84cad2..1accfa5f2dd 100644
--- a/distributed/worker.py
+++ b/distributed/worker.py
@@ -1864,15 +1864,17 @@ def handle_cancel_compute(self, key: str, stimulus_id: str) -> None:
 
     def handle_acquire_replicas(
         self,
-        who_has: dict[str, Collection[str]],
         *,
+        keys: Collection[str],
+        who_has: dict[str, Collection[str]],
         stimulus_id: str,
     ) -> None:
         if self.validate:
+            assert set(keys) == who_has.keys()
             assert all(who_has.values())
 
         recommendations: Recs = {}
-        for key in who_has:
+        for key in keys:
             ts = self.ensure_task_exists(
                 key=key,
                 # Transfer this data after all dependency tasks of computations with
@@ -1893,7 +1895,7 @@ def handle_acquire_replicas(
         self._handle_instructions(instructions)
 
         if self.validate:
-            for key in who_has:
+            for key in keys:
                 assert self.tasks[key].state != "released", self.story(key)
 
     def ensure_task_exists(