diff --git a/packages/@core-js/src/service/contractService.ts b/packages/@core-js/src/service/contractService.ts
index dd1d47ea0..b9522cdf5 100644
--- a/packages/@core-js/src/service/contractService.ts
+++ b/packages/@core-js/src/service/contractService.ts
@@ -11,6 +11,7 @@ import nacl from 'tweetnacl';
 export enum OpCodes {
   JETTON_TRANSFER = 0xf8a7ea5,
   NFT_TRANSFER = 0x5fcc3d14,
+  STONFI_SWAP = 0x25938561,
 }
 
 export enum WalletVersion {
diff --git a/packages/@core-js/src/service/transactionService.ts b/packages/@core-js/src/service/transactionService.ts
index 5aeb27bdb..5ee4dbdc3 100644
--- a/packages/@core-js/src/service/transactionService.ts
+++ b/packages/@core-js/src/service/transactionService.ts
@@ -104,6 +104,21 @@ export class TransactionService {
     let builder = beginCell();
 
     switch (opCode) {
+      case OpCodes.STONFI_SWAP:
+        builder = builder
+          .storeUint(OpCodes.STONFI_SWAP, 32)
+          .storeAddress(slice.loadAddress())
+          .storeCoins(slice.loadCoins())
+          .storeAddress(slice.loadAddress());
+
+        if (slice.loadBoolean()) {
+          slice.loadAddress();
+        }
+
+        return builder
+          .storeBit(1)
+          .storeAddress(Address.parse(customExcessesAccount))
+          .endCell();
       case OpCodes.NFT_TRANSFER:
         builder = builder
           .storeUint(OpCodes.NFT_TRANSFER, 32)
@@ -130,7 +145,11 @@ export class TransactionService {
         slice.loadMaybeAddress();
 
         while (slice.remainingRefs) {
-          builder = builder.storeRef(slice.loadRef());
+          const forwardCell = slice.loadRef();
+          // recursively rebuild forward payloads
+          builder = builder.storeRef(
+            this.rebuildBodyWithCustomExcessesAccount(forwardCell, customExcessesAccount),
+          );
         }
 
         return builder