From fa96b60113a701502629276f00270cf64aa78a6e Mon Sep 17 00:00:00 2001
From: Sangbida Chaudhuri <101164840+sangbida@users.noreply.github.com>
Date: Tue, 13 Jan 2026 22:52:11 +1030
Subject: [PATCH] lightningd: use bip86 derivation for anchor spend change
 outputs

---
 lightningd/anchorspend.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lightningd/anchorspend.c b/lightningd/anchorspend.c
index a194702ec..89cf224a4 100644
--- a/lightningd/anchorspend.c
+++ b/lightningd/anchorspend.c
@@ -276,7 +276,12 @@ static struct wally_psbt *anchor_psbt(const tal_t *ctx,
 		change = chainparams->dust_limit;
 	}
 
-	bip32_pubkey(ld, &final_key, channel->final_key_idx);
+	/* Use BIP86 derivation for P2TR if available, otherwise BIP32 */
+	if (ld->bip86_base) {
+		bip86_pubkey(ld, &final_key, channel->final_key_idx);
+	} else {
+		bip32_pubkey(ld, &final_key, channel->final_key_idx);
+	}
 	psbt_append_output(psbt,
 			   scriptpubkey_p2tr(tmpctx, &final_key),
 			   change);