diff --git a/web3.js/src/transaction.js b/web3.js/src/transaction.js
index a616621483..df7cbeafd5 100644
--- a/web3.js/src/transaction.js
+++ b/web3.js/src/transaction.js
@@ -18,8 +18,12 @@ export type TransactionSignature = string;
 
 /**
  * Maximum over-the-wire size of a Transaction
+ *
+ * 1280 is IPv6 minimum MTU
+ * 40 bytes is the size of the IPv6 header
+ * 8 bytes is the size of the fragment header
  */
-export const PACKET_DATA_SIZE = 512;
+export const PACKET_DATA_SIZE = 1280 - 40 - 8;
 
 /**
  * List of TransactionInstruction object fields that may be initialized at construction