diff --git a/src/crimson/os/alienstore/alien_collection.h b/src/crimson/os/alienstore/alien_collection.h
index 538db3dae66..17a930e77a9 100644
--- a/src/crimson/os/alienstore/alien_collection.h
+++ b/src/crimson/os/alienstore/alien_collection.h
@@ -21,6 +21,13 @@ public:
 
   template <typename Func, typename Result = std::invoke_result_t<Func>>
   seastar::futurize_t<Result> with_lock(Func&& func) {
+    // newer versions of Seastar provide two variants of `with_lock`
+    //   - generic, friendly towards throwing move constructors of Func,
+    //   - specialized for `noexcept`.
+    // unfortunately, the former has a limitation: the return value
+    // of `Func` must be compatible with `current_exception_as_future()`
+    // which boils down to returning `seastar::future<void>`.
+    static_assert(std::is_nothrow_move_constructible_v<Func>);
     return seastar::with_lock(mutex, std::forward<Func>(func));
   }
 
diff --git a/src/crimson/os/alienstore/alien_store.cc b/src/crimson/os/alienstore/alien_store.cc
index 3790b7d0604..904540a4c44 100644
--- a/src/crimson/os/alienstore/alien_store.cc
+++ b/src/crimson/os/alienstore/alien_store.cc
@@ -432,7 +432,8 @@ seastar::future<> AlienStore::do_transaction(CollectionRef ch,
     std::move(done),
     [this, ch, id] (auto &txn, auto &done) {
 	AlienCollection* alien_coll = static_cast<AlienCollection*>(ch.get());
-	return alien_coll->with_lock([this, ch, id, &txn, &done] {
+        // moving the `ch` is crucial for buildability on newer S* versions.
+	return alien_coll->with_lock([this, ch=std::move(ch), id, &txn, &done] {
 	  Context *crimson_wrapper =
 	    ceph::os::Transaction::collect_all_contexts(txn);
 	  assert(tp);
diff --git a/src/seastar b/src/seastar
index f43e1b1a417..e692a2d3fcf 160000
--- a/src/seastar
+++ b/src/seastar
@@ -1 +1 @@
-Subproject commit f43e1b1a4174caf9c507e1cfbece252a95dfd467
+Subproject commit e692a2d3fcf5593b7a00ab6900ee7e7762f989ac