From 8a8becaeab1aa518abf7743acb76b2ba3c8ea970 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Wed, 10 Jun 2026 20:03:13 +0200
Subject: [PATCH] beacon/engine: ensure nil ExecutionPayloadEnvelope.BlockValue
 doesn't crash (#35140)

Found while updating to go-ethereum master in prysm.
---
 beacon/engine/epe_encode.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/beacon/engine/epe_encode.go b/beacon/engine/epe_encode.go
index 73deb8f0c6..c44d87ec4f 100644
--- a/beacon/engine/epe_encode.go
+++ b/beacon/engine/epe_encode.go
@@ -66,7 +66,11 @@ func (e ExecutionPayloadEnvelope) MarshalJSON() ([]byte, error) {
 		b.RawValue(payload)
 
 		b.Key("blockValue")
-		b.HexBigInt(e.BlockValue)
+		if e.BlockValue != nil {
+			b.HexBigInt(e.BlockValue)
+		} else {
+			b.Null()
+		}
 
 		b.Key("blobsBundle")
 		marshalBlobsBundle(&b, e.BlobsBundle)