diff --git a/src/Storages/MergeTree/IMergeTreeDataPart.cpp b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
index 64cd4b940a1..98c67bed867 100644
--- a/src/Storages/MergeTree/IMergeTreeDataPart.cpp
+++ b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
@@ -1231,7 +1231,7 @@ catch (Exception & e)
 
 bool IMergeTreeDataPart::wasInvolvedInTransaction() const
 {
-    assert(!version.creation_tid.isEmpty());
+    assert(!version.creation_tid.isEmpty() || (state == State::Temporary /* && std::uncaught_exceptions() */));
     bool created_by_transaction = !version.creation_tid.isPrehistoric();
     bool removed_by_transaction = version.isRemovalTIDLocked() && version.removal_tid_lock != Tx::PrehistoricTID.getHash();
     return created_by_transaction || removed_by_transaction;
diff --git a/src/Storages/MergeTree/MutateTask.cpp b/src/Storages/MergeTree/MutateTask.cpp
index 49ae08a7e40..b6f8c3e62f7 100644
--- a/src/Storages/MergeTree/MutateTask.cpp
+++ b/src/Storages/MergeTree/MutateTask.cpp
@@ -1297,6 +1297,8 @@ bool MutateTask::prepare()
     }
 
     ctx->single_disk_volume = std::make_shared<SingleDiskVolume>("volume_" + ctx->future_part->name, ctx->space_reservation->getDisk(), 0);
+    /// FIXME new_data_part is not used in the case when we clone part with cloneAndLoadDataPartOnSameDisk and return false
+    /// Is it possible to handle this case earlier?
     ctx->new_data_part = ctx->data->createPart(
         ctx->future_part->name, ctx->future_part->type, ctx->future_part->part_info, ctx->single_disk_volume, "tmp_mut_" + ctx->future_part->name);
 
@@ -1363,7 +1365,7 @@ bool MutateTask::prepare()
             && ctx->files_to_rename.empty())
         {
             LOG_TRACE(ctx->log, "Part {} doesn't change up to mutation version {} (optimized)", ctx->source_part->name, ctx->future_part->part_info.mutation);
-            promise.set_value(ctx->data->cloneAndLoadDataPartOnSameDisk(ctx->source_part, "tmp_clone_", ctx->future_part->part_info, ctx->metadata_snapshot, ctx->txn));
+            promise.set_value(ctx->data->cloneAndLoadDataPartOnSameDisk(ctx->source_part, "tmp_mut_", ctx->future_part->part_info, ctx->metadata_snapshot, ctx->txn));
             return false;
         }