From ca153d40bf7720d5112858805a23b5fb02de2ba4 Mon Sep 17 00:00:00 2001
From: Weixie Cui <cuiweixie@gmail.com>
Date: Thu, 21 May 2026 20:00:00 +0800
Subject: [PATCH] eth: should return basefee for the next block as doc says

---
 eth/api_backend.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/eth/api_backend.go b/eth/api_backend.go
index 5e3558d8eb..c65ba5d27a 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -432,8 +432,10 @@ func (b *EthAPIBackend) FeeHistory(ctx context.Context, blockCount uint64, lastB
 }
 
 func (b *EthAPIBackend) BaseFee(ctx context.Context) *big.Int {
-	if b.ChainConfig().IsLondon(b.CurrentHeader().Number) {
-		return eip1559.CalcBaseFee(b.ChainConfig(), b.CurrentHeader())
+	header := b.CurrentHeader()
+	next := new(big.Int).Add(header.Number, common.Big1)
+	if b.ChainConfig().IsLondon(next) {
+		return eip1559.CalcBaseFee(b.ChainConfig(), header)
 	}
 	return nil
 }