diff --git a/src/mining/merkle_tree.go b/src/mining/merkle_tree.go
index 90dd75d..ae3f189 100644
--- a/src/mining/merkle_tree.go
+++ b/src/mining/merkle_tree.go
@@ -79,7 +79,7 @@ func CalcMerkleRoot(transactions []*transaction.Transaction, witness bool) [32]b
         if(witness){
             txids = append(txids, [32]byte(utils.DoubleHash(t.RawHex())))
         } else {
-            txids = append(txids, [32]byte(t.TxHash()))
+            txids = append(txids, [32]byte(utils.ReverseBytes(t.TxHash())))
         }
     }