diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index eaa29a4e3..64b6ab3b8 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -4,8 +4,8 @@ kotlinx-coroutines = "1.10.2"
 kotlinx-datetime = "0.6.2"
 kotlinx-serialization = "1.8.1"
 ktor = "3.1.2"
-bitcoinkmp = "0.25.1" # when upgrading bitcoin-kmp, keep secpjnijvm in sync!
-secpjnijvm = "0.18.0"
+bitcoinkmp = "0.26.0" # when upgrading bitcoin-kmp, keep secpjnijvm in sync!
+secpjnijvm = "0.19.0"
 kermit = "2.0.5"
 slf4j = "2.0.16"
 
diff --git a/modules/core/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt b/modules/core/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt
index 2a48ceef1..4cc8ffb80 100644
--- a/modules/core/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt
+++ b/modules/core/src/commonMain/kotlin/fr/acinq/lightning/channel/InteractiveTx.kt
@@ -733,7 +733,7 @@ data class InteractiveTxSession(
                     // Generate a secret nonce for this input if we don't already have one.
                     is InteractiveTxInput.LocalSwapIn -> when (secretNonces[inputOutgoing.serialId]) {
                         null -> {
-                            val secretNonce = Musig2.generateNonce(randomBytes32(), swapInKeys.userPrivateKey, swapInKeys.userPublicKey, listOf(swapInKeys.userPublicKey, swapInKeys.remoteServerPublicKey), null, null)
+                            val secretNonce = Musig2.generateNonce(randomBytes32(), Either.Left(swapInKeys.userPrivateKey), listOf(swapInKeys.userPublicKey, swapInKeys.remoteServerPublicKey), null, null)
                             secretNonces + (inputOutgoing.serialId to secretNonce)
                         }
                         else -> secretNonces
@@ -819,7 +819,7 @@ data class InteractiveTxSession(
             // Generate a secret nonce for this input if we don't already have one.
             is InteractiveTxInput.RemoteSwapIn -> when (secretNonces[input.serialId]) {
                 null -> {
-                    val secretNonce = Musig2.generateNonce(randomBytes32(), swapInKeys.localServerPrivateKey(remoteNodeId), input.serverKey, listOf(input.userKey, input.serverKey), null, null)
+                    val secretNonce = Musig2.generateNonce(randomBytes32(), Either.Right(input.serverKey), listOf(input.userKey, input.serverKey), null, null)
                     secretNonces + (input.serialId to secretNonce)
                 }
                 else -> secretNonces
diff --git a/modules/core/src/commonTest/kotlin/fr/acinq/lightning/transactions/TransactionsTestsCommon.kt b/modules/core/src/commonTest/kotlin/fr/acinq/lightning/transactions/TransactionsTestsCommon.kt
index 715c3a115..a0411eb1d 100644
--- a/modules/core/src/commonTest/kotlin/fr/acinq/lightning/transactions/TransactionsTestsCommon.kt
+++ b/modules/core/src/commonTest/kotlin/fr/acinq/lightning/transactions/TransactionsTestsCommon.kt
@@ -8,6 +8,7 @@ import fr.acinq.bitcoin.Script.pay2wsh
 import fr.acinq.bitcoin.Script.write
 import fr.acinq.bitcoin.crypto.Pack
 import fr.acinq.bitcoin.crypto.musig2.Musig2
+import fr.acinq.bitcoin.utils.Either
 import fr.acinq.lightning.CltvExpiry
 import fr.acinq.lightning.CltvExpiryDelta
 import fr.acinq.lightning.Lightning.randomBytes32
@@ -514,8 +515,8 @@ class TransactionsTestsCommon : LightningTestSuite() {
             )
             // The first step of a musig2 signing session is to exchange nonces.
             // If participants are disconnected before the end of the signing session, they must start again with fresh nonces.
-            val userNonce = Musig2.generateNonce(randomBytes32(), userPrivateKey, userPrivateKey.publicKey(), listOf(userPrivateKey.publicKey(), serverPrivateKey.publicKey()), null, null)
-            val serverNonce = Musig2.generateNonce(randomBytes32(), serverPrivateKey, serverPrivateKey.publicKey(), listOf(serverPrivateKey.publicKey(), userPrivateKey.publicKey()), null, null)
+            val userNonce = Musig2.generateNonce(randomBytes32(), Either.Left(userPrivateKey), listOf(userPrivateKey.publicKey(), serverPrivateKey.publicKey()), null, null)
+            val serverNonce = Musig2.generateNonce(randomBytes32(), Either.Left(serverPrivateKey), listOf(serverPrivateKey.publicKey(), userPrivateKey.publicKey()), null, null)
 
             // Once they have each other's public nonce, they can produce partial signatures.
             val userSig = swapInProtocol.signSwapInputUser(tx, 0, swapInTx.txOut, userPrivateKey, userNonce.first, userNonce.second, serverNonce.second).right!!