diff --git a/BTCPayServer/Services/PayjoinClient.cs b/BTCPayServer/Services/PayjoinClient.cs
index 8915a6d24..3e617bdba 100644
--- a/BTCPayServer/Services/PayjoinClient.cs
+++ b/BTCPayServer/Services/PayjoinClient.cs
@@ -34,7 +34,7 @@ namespace BTCPayServer.Services
             if (i.WitnessUtxo.ScriptPubKey.IsScriptType(ScriptType.P2WPKH))
                 return ScriptPubKeyType.Segwit;
             if (i.WitnessUtxo.ScriptPubKey.IsScriptType(ScriptType.P2SH) &&
-                i.FinalScriptWitness.ToScript().IsScriptType(ScriptType.P2WPKH))
+                i.FinalScriptWitness.GetSigner().ScriptPubKey.IsScriptType(ScriptType.P2WPKH))
                 return ScriptPubKeyType.SegwitP2SH;
             return null as ScriptPubKeyType?;
         }