diff --git a/kurtosis-devnet/interop.yaml b/kurtosis-devnet/interop.yaml
index 68ac3215413de..3dc05617d0dc5 100644
--- a/kurtosis-devnet/interop.yaml
+++ b/kurtosis-devnet/interop.yaml
@@ -74,6 +74,7 @@ optimism_package:
         fjord_time_offset: 0
         granite_time_offset: 0
         holocene_time_offset: 0
+        isthmus_time_offset: 0
         interop_time_offset: 0
         fund_dev_accounts: true
       batcher_params:
diff --git a/kurtosis-devnet/tests/isthmus/withdrawal_root_test.go b/kurtosis-devnet/tests/isthmus/withdrawal_root_test.go
index bfcee90e573c6..e7ac2ad7a4579 100644
--- a/kurtosis-devnet/tests/isthmus/withdrawal_root_test.go
+++ b/kurtosis-devnet/tests/isthmus/withdrawal_root_test.go
@@ -40,7 +40,11 @@ func withdrawalRootTestScenario(chainIdx uint64, userSentinel interface{}) syste
 		rpcCl, err := client.NewRPC(ctx, logger, chain.RPCURL())
 		require.NoError(t, err)
 		t.Cleanup(rpcCl.Close)
-		ethCl, err := sources.NewEthClient(rpcCl, logger, nil, &sources.EthClientConfig{})
+		ethCl, err := sources.NewEthClient(rpcCl, logger, nil, &sources.EthClientConfig{
+			MaxConcurrentRequests: 10,
+			MaxRequestsPerBatch:   int(10),
+			RPCProviderKind:       sources.RPCKindAny,
+		})
 		require.NoError(t, err)
 
 		gethCl, err := ethclient.DialContext(ctx, chain.RPCURL())