diff --git a/hydra-node/test/Hydra/Model/Payment.hs b/hydra-node/test/Hydra/Model/Payment.hs
index b5ef6dab88f..6be421cc140 100644
--- a/hydra-node/test/Hydra/Model/Payment.hs
+++ b/hydra-node/test/Hydra/Model/Payment.hs
@@ -86,7 +86,6 @@ instance IsTx Payment where
   type UTxOType Payment = [(CardanoSigningKey, Value)]
   type ValueType Payment = Value
   txId = error "undefined"
-  txSpendingUTxO = error "undefined"
   balance = foldMap snd
   hashUTxO = encodeUtf8 . show @Text