diff --git a/bench/cardano-topology/app/cardano-topology.hs b/bench/cardano-topology/app/cardano-topology.hs
index a3788fdd650..d07c0fb9267 100644
--- a/bench/cardano-topology/app/cardano-topology.hs
+++ b/bench/cardano-topology/app/cardano-topology.hs
@@ -327,7 +327,7 @@ writeProjectionFor' topology (BFT  i basePort p2pEnabled) = writeProjectionForPr
 writeProjectionFor' topology (Pool i basePort p2pEnabled) = writeProjectionForProducer topology i basePort p2pEnabled
 writeProjectionFor' topology (Explorer i basePort) = Aeson.encode $ Projection.projectionExplorer topology i basePort
 writeProjectionFor' _        ChaindbServer = "{Producers:[]}" -- ChainDB servers are just that.
-writeProjectionFor' topology Proxy = error "Nodes of kind \"proxy\" are not supported, Nix handles this case!"
+writeProjectionFor' _ Proxy = error "Nodes of kind \"proxy\" are not supported, Nix handles this case!"
 
 writeProjectionForProducer :: Topo.Topology -> Int -> Int -> Bool -> BSL8.ByteString
 writeProjectionForProducer topology i basePort enableP2P =