diff --git a/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs b/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
index ecf87a10391..4d034a70122 100644
--- a/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
+++ b/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
@@ -36,9 +36,6 @@ data ChainObservation
       }
   deriving stock (Eq, Show, Generic)
 
-instance Arbitrary ChainObservation where
-  arbitrary = genericArbitrary
-
 defaultObserverHandler :: Applicative m => ObserverHandler m
 defaultObserverHandler = const $ pure ()