1 files changed, 8 insertions, 0 deletions
diff --git a/src/mongo/db/op_observer/op_observer_impl.cpp b/src/mongo/db/op_observer/op_observer_impl.cpp
index 721189c13d2..a3a892fa516 100644
--- a/src/mongo/db/op_observer/op_observer_impl.cpp
+++ b/src/mongo/db/op_observer/op_observer_impl.cpp
@@ -813,6 +813,14 @@ void OpObserverImpl::onUpdate(OperationContext* opCtx, const OplogUpdateEntryArg
             operation.setChangeStreamPreImageRecordingMode(
                 ChangeStreamPreImageRecordingMode::kPreImagesCollection);
         }
+
+        auto collectionDescription =
+            CollectionShardingState::get(opCtx, args.nss)->getCollectionDescription(opCtx);
+        if (collectionDescription.isSharded()) {
+            operation.setPostImageDocumentKey(
+                collectionDescription.extractDocumentKey(args.updateArgs->updatedDoc).getOwned());
+        }
+
         operation.setDestinedRecipient(
             shardingWriteRouter.getReshardingDestinedRecipient(args.updateArgs->updatedDoc));
         operation.setFromMigrateIfTrue(args.updateArgs->source == OperationSource::kFromMigrate);