diff --git a/crates/engine/tree/src/tree/payload_processor/receipt_root_task.rs b/crates/engine/tree/src/tree/payload_processor/receipt_root_task.rs
index 993a57326d..08dfc575e8 100644
--- a/crates/engine/tree/src/tree/payload_processor/receipt_root_task.rs
+++ b/crates/engine/tree/src/tree/payload_processor/receipt_root_task.rs
@@ -77,8 +77,22 @@ impl<R: Receipt> ReceiptRootTaskHandle<R> {
             receipt_with_bloom.encode_2718(&mut encode_buf);
 
             aggregated_bloom |= *receipt_with_bloom.bloom_ref();
-            builder.push_unchecked(indexed_receipt.index, &encode_buf);
-            received_count += 1;
+            match builder.push(indexed_receipt.index, &encode_buf) {
+                Ok(()) => {
+                    received_count += 1;
+                }
+                Err(err) => {
+                    // If a duplicate or out-of-bounds index is streamed, skip it and
+                    // fall back to computing the receipt root from the full receipts
+                    // vector later.
+                    tracing::error!(
+                        target: "engine::tree::payload_processor",
+                        index = indexed_receipt.index,
+                        ?err,
+                        "Receipt root task received invalid receipt index, skipping"
+                    );
+                }
+            }
         }
 
         let Ok(root) = builder.finalize() else {
diff --git a/crates/engine/tree/src/tree/payload_validator.rs b/crates/engine/tree/src/tree/payload_validator.rs
index 637d9fb2ad..263c03957f 100644
--- a/crates/engine/tree/src/tree/payload_validator.rs
+++ b/crates/engine/tree/src/tree/payload_validator.rs
@@ -792,6 +792,11 @@ where
         // Execute transactions
         let exec_span = debug_span!(target: "engine::tree", "execution").entered();
         let mut transactions = transactions.into_iter();
+        // Some executors may execute transactions that do not append receipts during the
+        // main loop (e.g., system transactions whose receipts are added during finalization).
+        // In that case, invoking the callback on every transaction would resend the previous
+        // receipt with the same index and can panic the ordered root builder.
+        let mut last_sent_len = 0usize;
         loop {
             // Measure time spent waiting for next transaction from iterator
             // (e.g., parallel signature recovery)
@@ -818,10 +823,14 @@ where
             let gas_used = executor.execute_transaction(tx)?;
             self.metrics.record_transaction_execution(tx_start.elapsed());
 
-            // Send the latest receipt to the background task for incremental root computation
-            if let Some(receipt) = executor.receipts().last() {
-                let tx_index = executor.receipts().len() - 1;
-                let _ = receipt_tx.send(IndexedReceipt::new(tx_index, receipt.clone()));
+            let current_len = executor.receipts().len();
+            if current_len > last_sent_len {
+                last_sent_len = current_len;
+                // Send the latest receipt to the background task for incremental root computation.
+                if let Some(receipt) = executor.receipts().last() {
+                    let tx_index = current_len - 1;
+                    let _ = receipt_tx.send(IndexedReceipt::new(tx_index, receipt.clone()));
+                }
             }
 
             enter.record("gas_used", gas_used);