diff --git a/src/Interpreters/Squashing.h b/src/Interpreters/Squashing.h
old mode 100644
new mode 100755
index 05259bbc0c3..84e67e5d4c1
--- a/src/Interpreters/Squashing.h
+++ b/src/Interpreters/Squashing.h
@@ -32,10 +32,19 @@ public:
     explicit ApplySquashing(Block header_);
 
     Chunk add(Chunk && input_chunk);
-    const Block header;
+
+    void setHeader(Block header_)
+    {
+        header = header_;
+    }
+    Block getHeader()
+    {
+        return header;
+    }
 
 private:
     Chunk accumulated_chunk;
+    Block header;
 
     const ChunksToSquash * getInfoFromChunk(const Chunk & chunk);
 
diff --git a/src/Server/TCPHandler.cpp b/src/Server/TCPHandler.cpp
old mode 100644
new mode 100755
index 3cbaffe857a..77f84dba6e4
--- a/src/Server/TCPHandler.cpp
+++ b/src/Server/TCPHandler.cpp
@@ -912,9 +912,9 @@ AsynchronousInsertQueue::PushResult TCPHandler::processAsyncInsertQuery(Asynchro
     if (planned_chunk.hasChunkInfo())
         result_chunk = apply_squashing.add(std::move(planned_chunk));
     ColumnsWithTypeAndName cols;
-    if (result_chunk.hasColumns() && apply_squashing.header)
+    if (result_chunk.hasColumns() && apply_squashing.getHeader())
         for (size_t j = 0; j < result_chunk.getNumColumns(); ++ j)
-            cols.push_back(ColumnWithTypeAndName(result_chunk.getColumns()[j], apply_squashing.header.getDataTypes()[j], apply_squashing.header.getNames()[j]));
+            cols.push_back(ColumnWithTypeAndName(result_chunk.getColumns()[j], apply_squashing.getHeader().getDataTypes()[j], apply_squashing.getHeader().getNames()[j]));
     auto result = Block(cols);
     return insert_queue.pushQueryWithBlock(state.parsed_query, std::move(result), query_context);
 }
diff --git a/src/Storages/MergeTree/MutateTask.cpp b/src/Storages/MergeTree/MutateTask.cpp
old mode 100644
new mode 100755
index af36b7bb3e8..ff1d7c0b7c2
--- a/src/Storages/MergeTree/MutateTask.cpp
+++ b/src/Storages/MergeTree/MutateTask.cpp
@@ -1331,6 +1331,7 @@ bool PartMergerWriter::mutateOriginalPartAndPrepareProjections()
                 tmp_part.finalize();
                 tmp_part.part->getDataPartStorage().commitTransaction();
                 projection_parts[projection.name].emplace_back(std::move(tmp_part.part));
+                projection_squashes[i].setHeader(block_to_squash);
             }
         }
 
@@ -1351,9 +1352,9 @@ bool PartMergerWriter::mutateOriginalPartAndPrepareProjections()
         {
             Chunk projection_chunk = projection_squashes[i].add(std::move(planned_chunk));
             ColumnsWithTypeAndName cols;
-            if (projection_chunk.hasColumns() && projection_squashes[i].header)
+            if (projection_chunk.hasColumns() && projection_squashes[i].getHeader())
                 for (size_t j = 0; j < projection_chunk.getNumColumns(); ++j)
-                    cols.push_back(ColumnWithTypeAndName(projection_chunk.getColumns()[j], projection_squashes[i].header.getDataTypes()[j], projection_squashes[i].header.getNames()[j]));
+                    cols.push_back(ColumnWithTypeAndName(projection_chunk.getColumns()[j], projection_squashes[i].getHeader().getDataTypes()[j], projection_squashes[i].getHeader().getNames()[j]));
 
             auto temp_part = MergeTreeDataWriter::writeTempProjectionPart(
                 *ctx->data, ctx->log, Block(cols), projection, ctx->new_data_part.get(), ++block_num);