diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 8c38d7d037..7981f35ae3 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -1289,13 +1289,17 @@ func (api *BlockChainAPI) SimulateV1(ctx context.Context, opts simOpts, blockNrO
 	if state == nil || err != nil {
 		return nil, err
 	}
+	gasCap := api.b.RPCGasCap()
+	if gasCap == 0 {
+		gasCap = math.MaxUint64
+	}
 	sim := &simulator{
 		b:           api.b,
 		state:       state,
 		base:        base,
 		chainConfig: api.b.ChainConfig(),
 		// Each tx and all the series of txes shouldn't consume more gas than cap
-		gp:             new(core.GasPool).AddGas(api.b.RPCGasCap()),
+		gp:             new(core.GasPool).AddGas(gasCap),
 		traceTransfers: opts.TraceTransfers,
 		validate:       opts.Validation,
 		fullTx:         opts.ReturnFullTransactions,