diff --git a/src/Storages/MergeTree/ReplicatedMergeTreeSink.cpp b/src/Storages/MergeTree/ReplicatedMergeTreeSink.cpp
index 2d8bf28e700..a01ea2ab450 100644
--- a/src/Storages/MergeTree/ReplicatedMergeTreeSink.cpp
+++ b/src/Storages/MergeTree/ReplicatedMergeTreeSink.cpp
@@ -485,7 +485,8 @@ void ReplicatedMergeTreeSinkImpl<true>::finishDelayedChunk(const ZooKeeperWithFa
             auto conflict_block_ids = commitPart(zookeeper, partition.temp_part.part, partition.block_id, delayed_chunk->replicas_num, false);
             if (conflict_block_ids.empty())
                 break;
-            LOG_DEBUG(log, "Found depulicate block IDs: {}, retry times {}", toString(conflict_block_ids), ++retry_times);
+            ++retry_times;
+            LOG_DEBUG(log, "Found depulicate block IDs: {}, retry times {}", toString(conflict_block_ids), retry_times);
             /// partition clean conflict
             rewriteBlock(log, partition, conflict_block_ids);
             if (partition.block_id.empty())
diff --git a/tests/queries/0_stateless/02481_async_insert_dedup.python b/tests/queries/0_stateless/02481_async_insert_dedup.python
index 404165941b9..21cc3b5b401 100644
--- a/tests/queries/0_stateless/02481_async_insert_dedup.python
+++ b/tests/queries/0_stateless/02481_async_insert_dedup.python
@@ -106,6 +106,10 @@ while (True):
     errMsg = ""
     for i in range(total_number):
         expect = str(i+1)
+        if i >= len(result):
+            err = True
+            errMsg = "index {} is out of the size of result {}".format(i, len(result))
+            break
         real = result[i]
         if expect != real:
             err = True