diff --git a/src/IO/WriteBufferFromVector.h b/src/IO/WriteBufferFromVector.h
index 047e16643ce..54f43b6b591 100644
--- a/src/IO/WriteBufferFromVector.h
+++ b/src/IO/WriteBufferFromVector.h
@@ -36,8 +36,10 @@ private:
             throw Exception("WriteBufferFromVector is finished", ErrorCodes::CANNOT_WRITE_AFTER_END_OF_BUFFER);
 
         size_t old_size = vector.size();
+        /// pos may not be equal to vector.data() + old_size, because WriteBuffer::next() can be used to flush data
+        size_t pos_offset = pos - reinterpret_cast<Position>(vector.data());
         vector.resize(old_size * size_multiplier);
-        internal_buffer = Buffer(reinterpret_cast<Position>(vector.data() + old_size), reinterpret_cast<Position>(vector.data() + vector.size()));
+        internal_buffer = Buffer(reinterpret_cast<Position>(vector.data() + pos_offset), reinterpret_cast<Position>(vector.data() + vector.size()));
         working_buffer = internal_buffer;
     }