diff --git a/src/cryptonote_core/cryptonote_format_utils.cpp b/src/cryptonote_core/cryptonote_format_utils.cpp
index 7b7f1884..c5691d8f 100644
--- a/src/cryptonote_core/cryptonote_format_utils.cpp
+++ b/src/cryptonote_core/cryptonote_format_utils.cpp
@@ -595,7 +595,7 @@ namespace cryptonote
   {
     blobdata blob = t_serializable_object_to_blob(static_cast<block_header>(b));
     crypto::hash tree_root_hash = get_tx_tree_hash(b);
-    blob.append((const char*)&tree_root_hash, sizeof(tree_root_hash ));
+    blob.append(reinterpret_cast<const char*>(&tree_root_hash), sizeof(tree_root_hash));
     blob.append(tools::get_varint_data(b.tx_hashes.size()+1));
     return blob;
   }