diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index 410696cb4..fecd67729 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -1090,7 +1090,14 @@ namespace cryptonote
 
     // we still need the size
     if (blob_size)
-      *blob_size = get_object_blobsize(t);
+    {
+      if (!t.is_blob_size_valid())
+      {
+        t.blob_size = blob.size();
+        t.set_blob_size_valid(true);
+      }
+      *blob_size = t.blob_size;
+    }
 
     return true;
   }
@@ -1156,8 +1163,12 @@ namespace cryptonote
     if (!hash_result)
       return false;
 
-    if (get_block_height(b) != 202612)
-      return true;
+    if (b.miner_tx.vin.size() == 1 && b.miner_tx.vin[0].type() == typeid(cryptonote::txin_gen))
+    {
+      const cryptonote::txin_gen &txin_gen = boost::get<cryptonote::txin_gen>(b.miner_tx.vin[0]);
+      if (txin_gen.height != 202612)
+        return true;
+    }
 
     // EXCEPTION FOR BLOCK 202612
     const std::string correct_blob_hash_202612 = "3a8a2b3a29b50fc86ff73dd087ea43c6f0d6b8f936c849194d5c84c737903966";
@@ -1212,9 +1223,9 @@ namespace cryptonote
   bool get_block_longhash(const block& b, crypto::hash& res, uint64_t height)
   {
     // block 202612 bug workaround
-    const std::string longhash_202612 = "84f64766475d51837ac9efbef1926486e58563c95a19fef4aec3254f03000000";
     if (height == 202612)
     {
+      static const std::string longhash_202612 = "84f64766475d51837ac9efbef1926486e58563c95a19fef4aec3254f03000000";
       string_tools::hex_to_pod(longhash_202612, res);
       return true;
     }
@@ -1315,6 +1326,7 @@ namespace cryptonote
   crypto::hash get_tx_tree_hash(const block& b)
   {
     std::vector<crypto::hash> txs_ids;
+    txs_ids.reserve(1 + b.tx_hashes.size());
     crypto::hash h = null_hash;
     size_t bl_sz = 0;
     get_transaction_hash(b.miner_tx, h, bl_sz);