diff --git a/lib/arkecosystem/crypto/transactions/transaction.rb b/lib/arkecosystem/crypto/transactions/transaction.rb
index 0fd4096..9945f8c 100644
--- a/lib/arkecosystem/crypto/transactions/transaction.rb
+++ b/lib/arkecosystem/crypto/transactions/transaction.rb
@@ -58,7 +58,7 @@ def to_bytes(skip_signature = true, skip_second_signature = true)
           if @vendor_field
             bytes << @vendor_field
 
-            if @vendor_field.size < 64
+            if @vendor_field.size < 65
               bytes << [].pack("x#{64 - @vendor_field.size}")
             end
           else